From 9f9d6698312de91261fed15ac1dc8bb9d0dc6d3c Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Mon, 24 Aug 2026 22:56:04 +0200
Subject: [PATCH 01/20] feat(editor): add audio-track data model for external
 audio import
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Phase 1 of issue #350 (import voiceover / BGM / SFX). Adds the document
model for timeline audio tracks without any UI, IPC, or export wiring yet.

- Widen assetSchema.kind to enum(["video","audio"]) so an imported audio
  file (no video stream) has its own kind. Additive — every existing doc
  holds "video", which still validates, so no schemaVersion bump.
- Add audioTrackSchema: a timeline-global track addressed in OUTPUT
  (post-trim/post-speed) timeline seconds, the same domain the compositor's
  concatenated programme PCM lives in. That invariant is what will keep the
  live preview and the export in sync in later phases.
- Add document.audioTracks[] (defaulted, so pre-#350 docs load unchanged),
  the AxcutAudioTrack type, and a createAudioTrack factory.
- Tests cover defaults, trim/position validation, factory round-trip, the
  kind widening, and that a document omitting audioTracks defaults to [].
- Fixture fallout: 15 test files + browserShim build full AxcutDocument
  literals and now carry audioTracks: [] alongside their zoomRanges: [].

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 .../ai-edition/EditorEmptyState.test.tsx      |   1 +
 .../ExportDialog.showInFolder.test.tsx        |   1 +
 .../ai-edition/ExportDialog.test.ts           |   1 +
 .../ai-edition/WebcamOverlay.test.tsx         |   1 +
 .../ai-edition/document/outputFormat.test.ts  |   1 +
 src/lib/ai-edition/document/timeline.test.ts  |   1 +
 .../ai-edition/document/transcribe.test.ts    |   1 +
 src/lib/ai-edition/schema/index.test.ts       | 102 ++++++++++++++++--
 src/lib/ai-edition/schema/index.ts            |  65 ++++++++++-
 .../ai-edition/store/editorSettings.test.ts   |   1 +
 src/lib/ai-edition/store/projectStore.test.ts |   1 +
 .../ai-edition/store/undo.modalGuard.test.tsx |   1 +
 src/lib/ai-edition/store/useCaptions.test.ts  |   1 +
 .../store/useEditorSettings.test.ts           |   1 +
 src/lib/ai-edition/store/useTimeline.test.ts  |   1 +
 .../ai-edition/transcription/status.test.ts   |   1 +
 src/native/browserShim.ts                     |   1 +
 src/native/sceneDescription.test.ts           |   1 +
 18 files changed, 175 insertions(+), 8 deletions(-)

diff --git a/src/components/ai-edition/EditorEmptyState.test.tsx b/src/components/ai-edition/EditorEmptyState.test.tsx
index acb513e4b..be7f130b7 100644
--- a/src/components/ai-edition/EditorEmptyState.test.tsx
+++ b/src/components/ai-edition/EditorEmptyState.test.tsx
@@ -53,6 +53,7 @@ const sampleDoc = vi.hoisted(
 		},
 		annotations: [],
 		zoomRanges: [],
+		audioTracks: [],
 		legacyEditor: null,
 	}),
 );
diff --git a/src/components/ai-edition/ExportDialog.showInFolder.test.tsx b/src/components/ai-edition/ExportDialog.showInFolder.test.tsx
index 835d9c8fd..db4207c4e 100644
--- a/src/components/ai-edition/ExportDialog.showInFolder.test.tsx
+++ b/src/components/ai-edition/ExportDialog.showInFolder.test.tsx
@@ -75,6 +75,7 @@ const DOC: AxcutDocument = {
 	},
 	annotations: [],
 	zoomRanges: [],
+	audioTracks: [],
 	legacyEditor: null,
 };
 
diff --git a/src/components/ai-edition/ExportDialog.test.ts b/src/components/ai-edition/ExportDialog.test.ts
index 3aa8d85b5..ed2f1ab1a 100644
--- a/src/components/ai-edition/ExportDialog.test.ts
+++ b/src/components/ai-edition/ExportDialog.test.ts
@@ -57,6 +57,7 @@ function doc(assets: AxcutAsset[], clips: AxcutClip[]): AxcutDocument {
 		},
 		annotations: [],
 		zoomRanges: [],
+		audioTracks: [],
 		legacyEditor: null,
 	};
 }
diff --git a/src/components/ai-edition/WebcamOverlay.test.tsx b/src/components/ai-edition/WebcamOverlay.test.tsx
index bdd36a558..9c4b2762d 100644
--- a/src/components/ai-edition/WebcamOverlay.test.tsx
+++ b/src/components/ai-edition/WebcamOverlay.test.tsx
@@ -74,6 +74,7 @@ function makeDocument(): AxcutDocument {
 		},
 		annotations: [],
 		zoomRanges: [],
+		audioTracks: [],
 		legacyEditor: null,
 	};
 }
diff --git a/src/lib/ai-edition/document/outputFormat.test.ts b/src/lib/ai-edition/document/outputFormat.test.ts
index 4ceac442f..c7e75ab40 100644
--- a/src/lib/ai-edition/document/outputFormat.test.ts
+++ b/src/lib/ai-edition/document/outputFormat.test.ts
@@ -67,6 +67,7 @@ function doc(assets: AxcutAsset[], clips: AxcutClip[]): AxcutDocument {
 		},
 		annotations: [],
 		zoomRanges: [],
+		audioTracks: [],
 		legacyEditor: null,
 	};
 }
diff --git a/src/lib/ai-edition/document/timeline.test.ts b/src/lib/ai-edition/document/timeline.test.ts
index a561dd2f9..bb5172178 100644
--- a/src/lib/ai-edition/document/timeline.test.ts
+++ b/src/lib/ai-edition/document/timeline.test.ts
@@ -57,6 +57,7 @@ function makeDoc(overrides: Partial<AxcutDocument> = {}): AxcutDocument {
 		},
 		annotations: [],
 		zoomRanges: [],
+		audioTracks: [],
 		legacyEditor: null,
 		...overrides,
 	};
diff --git a/src/lib/ai-edition/document/transcribe.test.ts b/src/lib/ai-edition/document/transcribe.test.ts
index 72dc8d00b..9e8cbe4bd 100644
--- a/src/lib/ai-edition/document/transcribe.test.ts
+++ b/src/lib/ai-edition/document/transcribe.test.ts
@@ -49,6 +49,7 @@ function makeDoc(): AxcutDocument {
 		},
 		annotations: [],
 		zoomRanges: [],
+		audioTracks: [],
 		legacyEditor: null,
 	};
 }
diff --git a/src/lib/ai-edition/schema/index.test.ts b/src/lib/ai-edition/schema/index.test.ts
index bbba94fd8..2c6b25be4 100644
--- a/src/lib/ai-edition/schema/index.test.ts
+++ b/src/lib/ai-edition/schema/index.test.ts
@@ -3,8 +3,10 @@ import { migrateRawDocumentToCurrent } from "../document/migrate";
 import {
 	annotationRegionSchema,
 	assetSchema,
+	audioTrackSchema,
 	axcutSchemaVersion,
 	clipSchema,
+	createAudioTrack,
 	createEmptyDocument,
 	documentSchema,
 	ensureDocument,
@@ -40,6 +42,7 @@ describe("axcut-schema v7", () => {
 		expect(doc.timeline.captionRanges).toEqual([]);
 		expect(doc.annotations).toEqual([]);
 		expect(doc.zoomRanges).toEqual([]);
+		expect(doc.audioTracks).toEqual([]);
 		expect(doc.transcripts).toEqual([]);
 		expect(doc.legacyEditor).toBeNull();
 	});
@@ -73,14 +76,22 @@ describe("axcut-schema v7", () => {
 		).toThrow();
 	});
 
-	it("assetSchema requires kind = 'video'", () => {
+	it("assetSchema accepts kind 'video' and 'audio', defaulting to 'video'", () => {
+		// Widened from a literal when external-audio import landed (issue #350).
+		const video = assetSchema.parse({ id: "a1", label: "x", originalPath: "/x.mp4" });
+		expect(video.kind).toBe("video");
+		const audio = assetSchema.parse({
+			id: "a2",
+			kind: "audio",
+			label: "bgm",
+			originalPath: "/bgm.mp3",
+		});
+		expect(audio.kind).toBe("audio");
+	});
+
+	it("assetSchema rejects an unknown kind", () => {
 		expect(() =>
-			assetSchema.parse({
-				id: "asset_1",
-				kind: "audio",
-				label: "x",
-				originalPath: "/x.mp4",
-			}),
+			assetSchema.parse({ id: "a1", kind: "image", label: "x", originalPath: "/x.png" }),
 		).toThrow();
 	});
 
@@ -962,3 +973,80 @@ describe("v6 -> v7 trim clip-anchor migration", () => {
 		]);
 	});
 });
+
+describe("audio tracks (issue #350)", () => {
+	it("applies defaults for gain, mute, trim, position, and label", () => {
+		const track = audioTrackSchema.parse({
+			id: "audio_1",
+			assetId: "asset_1",
+			durationSec: 42,
+		});
+		expect(track.timelineStartSec).toBe(0);
+		expect(track.trimStartSec).toBe(0);
+		expect(track.trimEndSec).toBeUndefined();
+		expect(track.gainDb).toBe(0);
+		expect(track.mute).toBe(false);
+		expect(track.label).toBe("");
+	});
+
+	it("rejects a trim window whose end precedes its start", () => {
+		expect(() =>
+			audioTrackSchema.parse({
+				id: "audio_1",
+				assetId: "asset_1",
+				durationSec: 10,
+				trimStartSec: 5,
+				trimEndSec: 2,
+			}),
+		).toThrow();
+	});
+
+	it("rejects a negative timelineStartSec", () => {
+		expect(() =>
+			audioTrackSchema.parse({
+				id: "audio_1",
+				assetId: "asset_1",
+				durationSec: 10,
+				timelineStartSec: -1,
+			}),
+		).toThrow();
+	});
+
+	it("createAudioTrack builds a schema-valid track with a prefixed id", () => {
+		const track = createAudioTrack({
+			assetId: "asset_1",
+			durationSec: 12.5,
+			timelineStartSec: 3,
+			label: "voiceover.mp3",
+		});
+		expect(track.id).toMatch(/^audio_/);
+		expect(track.assetId).toBe("asset_1");
+		expect(track.durationSec).toBe(12.5);
+		expect(track.timelineStartSec).toBe(3);
+		expect(track.label).toBe("voiceover.mp3");
+		// The factory output must itself round-trip through the schema.
+		expect(() => audioTrackSchema.parse(track)).not.toThrow();
+	});
+
+	it("defaults audioTracks to [] when a stored document omits the key", () => {
+		// A document written before issue #350 has no `audioTracks`; the defaulted
+		// array must fill in so older files load unchanged (no schemaVersion bump).
+		const { audioTracks: _drop, ...withoutAudio } = createEmptyDocument({
+			projectId: "p",
+			title: "t",
+		});
+		expect("audioTracks" in withoutAudio).toBe(false);
+		const parsed = documentSchema.parse(withoutAudio);
+		expect(parsed.audioTracks).toEqual([]);
+	});
+
+	it("round-trips a document carrying an audio track", () => {
+		const track = createAudioTrack({ assetId: "asset_1", durationSec: 8 });
+		const doc = {
+			...createEmptyDocument({ projectId: "p", title: "t" }),
+			audioTracks: [track],
+		};
+		const parsed = documentSchema.parse(doc);
+		expect(parsed.audioTracks).toEqual([track]);
+	});
+});
diff --git a/src/lib/ai-edition/schema/index.ts b/src/lib/ai-edition/schema/index.ts
index dd6936fde..a6efe746b 100644
--- a/src/lib/ai-edition/schema/index.ts
+++ b/src/lib/ai-edition/schema/index.ts
@@ -150,7 +150,12 @@ export const assetTranscriptionFailureSchema = z.object({
 
 export const assetSchema = z.object({
 	id: z.string().min(1),
-	kind: z.literal("video"),
+	// Widened from a `"video"` literal when external-audio import landed (issue
+	// #350). An imported voiceover / BGM / SFX file carries no video stream, so it
+	// needs its own kind; every document written before this only ever held
+	// `"video"`, which still validates, so the widening is additive (no
+	// schemaVersion bump — same rule as `transcriptionFailure` below).
+	kind: z.enum(["video", "audio"]).default("video"),
 	label: z.string().min(1),
 	originalPath: z.string().min(1),
 	proxyPath: z.string().optional(),
@@ -471,6 +476,38 @@ export const zoomRegionSchema = endGteStart(
 	"startMs",
 );
 
+// External audio import (issue #350) — voiceover / BGM / SFX layered over the
+// assembled programme. Unlike zoom/speed/annotation/trim, an audio track is NOT
+// clip-anchored: it floats over the whole timeline, so it is addressed in OUTPUT
+// (post-trim, post-speed) timeline seconds — the same domain the compositor's
+// concatenated programme PCM lives in (see `SceneAudio` in
+// src/native/sceneDescription.ts and `audio.rs`). That single invariant is what
+// keeps the live preview and the export in sync without a per-track sync offset.
+//
+// `assetId` points at an asset with `kind: "audio"`. `timelineStartSec` places
+// the track's head on the programme; `trimStartSec`/`trimEndSec` window the
+// source file (both in source seconds); `gainDb` + `mute` set its level.
+export const audioTrackSchema = z
+	.object({
+		id: z.string().min(1),
+		assetId: z.string().min(1),
+		timelineStartSec: z.number().nonnegative().default(0),
+		// Full source duration of the underlying file, cached here so the timeline
+		// can lay out the pill before the asset is re-probed on load.
+		durationSec: z.number().nonnegative().default(0),
+		trimStartSec: z.number().nonnegative().default(0),
+		// Absent means "play to the end of the file". Explicit when the user trims
+		// the tail so the pill and the export agree on where the track stops.
+		trimEndSec: z.number().nonnegative().optional(),
+		gainDb: z.number().default(0),
+		mute: z.boolean().default(false),
+		label: z.string().default(""),
+	})
+	.refine((data) => data.trimEndSec === undefined || data.trimEndSec >= data.trimStartSec, {
+		message: "trimEndSec must be greater than or equal to trimStartSec",
+		path: ["trimEndSec"],
+	});
+
 // Legacy OpenScreen appearance / export settings that the v3 schema doesn't
 // normalize into the timeline / assets model. They are applied at export time
 // by the existing pipeline (see technical-documentation/architecture/document-model.md).
@@ -503,6 +540,9 @@ const documentSchemaShape = z.object({
 	}),
 	annotations: z.array(annotationRegionSchema).default([]),
 	zoomRanges: z.array(zoomRegionSchema).default([]),
+	// Imported audio tracks (issue #350). Defaulted so every document written
+	// before this loads unchanged; an older build simply strips the key on save.
+	audioTracks: z.array(audioTrackSchema).default([]),
 	legacyEditor: legacyEditorSchema.nullable().default(null),
 });
 
@@ -944,6 +984,7 @@ export type AxcutTimelineOperation = z.infer<typeof timelineOperationSchema>;
 export type AxcutAnnotationRegion = z.infer<typeof annotationRegionSchema>;
 export type AxcutZoomRegion = z.infer<typeof zoomRegionSchema>;
 export type AxcutCameraTrack = z.infer<typeof cameraTrackSchema>;
+export type AxcutAudioTrack = z.infer<typeof audioTrackSchema>;
 export type AxcutLegacyEditor = z.infer<typeof legacyEditorSchema>;
 export type AxcutDocument = z.infer<typeof documentSchema>;
 export type AxcutDocumentInput = z.input<typeof documentSchema>;
@@ -979,6 +1020,7 @@ export function createEmptyDocument(
 		},
 		annotations: [],
 		zoomRanges: [],
+		audioTracks: [],
 		legacyEditor: null,
 	});
 }
@@ -986,3 +1028,24 @@ export function createEmptyDocument(
 export function ensureDocument(value: unknown): AxcutDocument {
 	return documentSchema.parse(value);
 }
+
+/**
+ * Build a timeline audio track for an imported audio asset (issue #350). The
+ * head is placed at `timelineStartSec` (output-timeline seconds) and the track
+ * spans the whole source file until the user trims it. Parsed through the schema
+ * so every default (gain, mute, trim) is applied in one place.
+ */
+export function createAudioTrack(input: {
+	assetId: string;
+	durationSec: number;
+	timelineStartSec?: number;
+	label?: string;
+}): AxcutAudioTrack {
+	return audioTrackSchema.parse({
+		id: createId("audio"),
+		assetId: input.assetId,
+		durationSec: input.durationSec,
+		timelineStartSec: input.timelineStartSec ?? 0,
+		label: input.label ?? "",
+	});
+}
diff --git a/src/lib/ai-edition/store/editorSettings.test.ts b/src/lib/ai-edition/store/editorSettings.test.ts
index 07982f47a..0848d3404 100644
--- a/src/lib/ai-edition/store/editorSettings.test.ts
+++ b/src/lib/ai-edition/store/editorSettings.test.ts
@@ -29,6 +29,7 @@ const baseDoc: AxcutDocument = {
 	},
 	annotations: [],
 	zoomRanges: [],
+	audioTracks: [],
 	transcripts: [],
 	transcript: null,
 	legacyEditor: null,
diff --git a/src/lib/ai-edition/store/projectStore.test.ts b/src/lib/ai-edition/store/projectStore.test.ts
index a46a6b535..84074aad2 100644
--- a/src/lib/ai-edition/store/projectStore.test.ts
+++ b/src/lib/ai-edition/store/projectStore.test.ts
@@ -62,6 +62,7 @@ const sampleDoc = {
 	},
 	annotations: [],
 	zoomRanges: [],
+	audioTracks: [],
 	legacyEditor: null,
 };
 
diff --git a/src/lib/ai-edition/store/undo.modalGuard.test.tsx b/src/lib/ai-edition/store/undo.modalGuard.test.tsx
index f54b12389..46e083b0b 100644
--- a/src/lib/ai-edition/store/undo.modalGuard.test.tsx
+++ b/src/lib/ai-edition/store/undo.modalGuard.test.tsx
@@ -35,6 +35,7 @@ function doc(title: string): AxcutDocument {
 		},
 		annotations: [],
 		zoomRanges: [],
+		audioTracks: [],
 		legacyEditor: null,
 	};
 }
diff --git a/src/lib/ai-edition/store/useCaptions.test.ts b/src/lib/ai-edition/store/useCaptions.test.ts
index b4063d68c..0cd641328 100644
--- a/src/lib/ai-edition/store/useCaptions.test.ts
+++ b/src/lib/ai-edition/store/useCaptions.test.ts
@@ -71,6 +71,7 @@ const docA: AxcutDocument = {
 	},
 	annotations: [],
 	zoomRanges: [],
+	audioTracks: [],
 	legacyEditor: null,
 };
 
diff --git a/src/lib/ai-edition/store/useEditorSettings.test.ts b/src/lib/ai-edition/store/useEditorSettings.test.ts
index bd47cb452..4122c05bf 100644
--- a/src/lib/ai-edition/store/useEditorSettings.test.ts
+++ b/src/lib/ai-edition/store/useEditorSettings.test.ts
@@ -74,6 +74,7 @@ const docA: AxcutDocument = {
 	},
 	annotations: [],
 	zoomRanges: [],
+	audioTracks: [],
 	legacyEditor: null,
 };
 
diff --git a/src/lib/ai-edition/store/useTimeline.test.ts b/src/lib/ai-edition/store/useTimeline.test.ts
index 78854e817..ef28cd571 100644
--- a/src/lib/ai-edition/store/useTimeline.test.ts
+++ b/src/lib/ai-edition/store/useTimeline.test.ts
@@ -110,6 +110,7 @@ const sampleDoc: AxcutDocument = {
 	},
 	annotations: [],
 	zoomRanges: [],
+	audioTracks: [],
 	legacyEditor: null,
 };
 
diff --git a/src/lib/ai-edition/transcription/status.test.ts b/src/lib/ai-edition/transcription/status.test.ts
index 00261712e..82b282703 100644
--- a/src/lib/ai-edition/transcription/status.test.ts
+++ b/src/lib/ai-edition/transcription/status.test.ts
@@ -243,6 +243,7 @@ describe("transcriptRelevantAssetIds", () => {
 		transcripts: [],
 		annotations: [],
 		zoomRanges: [],
+		audioTracks: [],
 		legacyEditor: null,
 	};
 
diff --git a/src/native/browserShim.ts b/src/native/browserShim.ts
index 8ef5989a8..c00f53d51 100644
--- a/src/native/browserShim.ts
+++ b/src/native/browserShim.ts
@@ -386,6 +386,7 @@ function createShimBridgeClient() {
 					},
 					annotations: [],
 					zoomRanges: [],
+					audioTracks: [],
 					legacyEditor: null,
 				};
 				documentsByProject[doc.project.id] = doc;
diff --git a/src/native/sceneDescription.test.ts b/src/native/sceneDescription.test.ts
index 570ae71ee..2c02137e0 100644
--- a/src/native/sceneDescription.test.ts
+++ b/src/native/sceneDescription.test.ts
@@ -91,6 +91,7 @@ function makeDoc(
 		},
 		annotations: overrides.annotations ?? [],
 		zoomRanges: overrides.zoomRanges ?? [],
+		audioTracks: overrides.audioTracks ?? [],
 		legacyEditor: overrides.legacyEditor ?? null,
 	};
 }

From 95e80d673ec7d54ca53908a00e35b713381334ca Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Mon, 24 Aug 2026 23:27:03 +0200
Subject: [PATCH 02/20] feat(editor): import external audio files as audio-kind
 assets
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Phase 2 of issue #350. Wires up picking an external audio file (voiceover
/ BGM / SFX) and adding it to a project as a kind:"audio" asset. No
timeline placement, preview, or export yet.

- IPC: open-audio-file-picker mirrors the video picker but approves against
  a dedicated audio extension set (mp3/wav/m4a/aac/flac/ogg/opus). Factor the
  path approver into a shared approveReadableMediaPath so the audio and video
  approvers differ only by their extension gate — an audio picker must not
  approve a video path or vice versa.
- document-service.addAsset takes a kind; an audio import validates against
  audio extensions and never claims the empty primaryAssetId slot, so a BGM
  file dropped into a fresh project can't become its primary (video) asset.
  Threaded kind through the bridge chain (contracts, client, nativeBridge,
  aiEditionService) and the browser shim.
- projectStore.addAudioAsset imports the file, skips the camera-sidecar
  lookup addAsset does, and probes the real duration up front (new
  probeAudioDuration, the <audio> counterpart of probeVideoDuration) so the
  timeline can size the track in a later phase.
- i18n: selectAudio / audioFiles dialog strings across all 13 locales
  (English placeholders for the untranslated 12).
- Tests: document-service audio branch (kind, primary guard, extension
  routing), probeAudioDuration (shared harness, driven per media tag), and
  addAudioAsset (bridge kind arg, no camera lookup, duration stamping).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 electron/ai-edition/document-service.test.ts  | 42 +++++++++
 electron/ai-edition/document-service.ts       | 41 ++++++++-
 electron/electron-env.d.ts                    |  8 ++
 electron/ipc/handlers.ts                      | 90 ++++++++++++++++++-
 electron/ipc/nativeBridge.ts                  |  1 +
 .../services/aiEditionService.ts              | 14 ++-
 electron/preload.ts                           |  3 +
 src/i18n/locales/ar/dialogs.json              |  2 +
 src/i18n/locales/en/dialogs.json              |  2 +
 src/i18n/locales/es/dialogs.json              |  2 +
 src/i18n/locales/fr/dialogs.json              |  2 +
 src/i18n/locales/it/dialogs.json              |  2 +
 src/i18n/locales/ja-JP/dialogs.json           |  2 +
 src/i18n/locales/ko-KR/dialogs.json           |  2 +
 src/i18n/locales/pt-BR/dialogs.json           |  2 +
 src/i18n/locales/ru/dialogs.json              |  2 +
 src/i18n/locales/tr/dialogs.json              |  2 +
 src/i18n/locales/vi/dialogs.json              |  2 +
 src/i18n/locales/zh-CN/dialogs.json           |  2 +
 src/i18n/locales/zh-TW/dialogs.json           |  2 +
 src/lib/ai-edition/schema/index.ts            |  4 +
 src/lib/ai-edition/store/projectStore.test.ts | 75 ++++++++++++++++
 src/lib/ai-edition/store/projectStore.ts      | 55 +++++++++++-
 src/lib/ai-edition/timeline/duration.test.ts  | 29 +++---
 src/lib/ai-edition/timeline/duration.ts       | 58 ++++++++++++
 src/native/browserShim.ts                     | 15 +++-
 src/native/client.ts                          |  4 +-
 src/native/contracts.ts                       |  2 +-
 28 files changed, 440 insertions(+), 27 deletions(-)

diff --git a/electron/ai-edition/document-service.test.ts b/electron/ai-edition/document-service.test.ts
index 6cbdb97c9..91e780acf 100644
--- a/electron/ai-edition/document-service.test.ts
+++ b/electron/ai-edition/document-service.test.ts
@@ -280,6 +280,48 @@ describe("DocumentService", () => {
 			expect(after.project.primaryAssetId).toBe(first.project.primaryAssetId);
 			expect(after.assets).toHaveLength(2);
 		});
+
+		// Issue #350 — external audio import (voiceover / BGM / SFX).
+		it("appends an audio asset without claiming the primary slot", async () => {
+			const doc = await service.createProject("P");
+			const updated = await service.addAsset(doc.project.id, {
+				path: "/tmp/voiceover.mp3",
+				kind: "audio",
+			});
+			expect(updated.assets).toHaveLength(1);
+			expect(updated.assets[0]?.kind).toBe("audio");
+			// An audio-only file must never become the project's primary asset, even
+			// when it is the first file added to an otherwise-empty project.
+			expect(updated.project.primaryAssetId).toBeUndefined();
+		});
+
+		it("keeps the existing video primary when an audio track is added", async () => {
+			const doc = await service.createProject("P");
+			const withVideo = await service.addAsset(doc.project.id, { path: "/tmp/screen.mp4" });
+			const primary = withVideo.project.primaryAssetId;
+			const withAudio = await service.addAsset(doc.project.id, {
+				path: "/tmp/bgm.wav",
+				kind: "audio",
+			});
+			expect(withAudio.project.primaryAssetId).toBe(primary);
+			expect(withAudio.assets).toHaveLength(2);
+		});
+
+		it("rejects unsupported audio extensions", async () => {
+			const doc = await service.createProject("P");
+			await expect(
+				service.addAsset(doc.project.id, { path: "/tmp/clip.mp4", kind: "audio" }),
+			).rejects.toBeInstanceOf(ProjectFileError);
+		});
+
+		it("accepts a video extension under the default kind but not as audio", async () => {
+			const doc = await service.createProject("P");
+			// The same extension routing works in reverse: an .mp3 is fine as audio
+			// but rejected as video (covered above), and an .mp4 is the opposite.
+			await expect(
+				service.addAsset(doc.project.id, { path: "/tmp/a.mp3", kind: "audio" }),
+			).resolves.toBeDefined();
+		});
 	});
 
 	describe("removeAsset", () => {
diff --git a/electron/ai-edition/document-service.ts b/electron/ai-edition/document-service.ts
index 3c93e3bc0..f519379e4 100644
--- a/electron/ai-edition/document-service.ts
+++ b/electron/ai-edition/document-service.ts
@@ -38,6 +38,9 @@ export interface ProjectSummary {
 export interface AddAssetInput {
 	path: string;
 	label?: string;
+	// "audio" imports an external voiceover / BGM / SFX file (issue #350).
+	// Defaults to "video" when omitted, so existing callers are unaffected.
+	kind?: "video" | "audio";
 }
 
 export class DocumentNotFoundError extends Error {
@@ -72,6 +75,24 @@ function isSupportedVideoPath(filePath: string): boolean {
 	return SUPPORTED_VIDEO_EXTENSIONS.has(ext);
 }
 
+// Imported audio (issue #350). Decoding is handled downstream by the same
+// WebCodecs / ffmpeg paths that read a video's audio track, so this list is the
+// container formats decodeAudioData and the compositor can open.
+const SUPPORTED_AUDIO_EXTENSIONS = new Set([
+	".mp3",
+	".wav",
+	".m4a",
+	".aac",
+	".flac",
+	".ogg",
+	".opus",
+]);
+
+function isSupportedAudioPath(filePath: string): boolean {
+	const ext = path.extname(filePath).toLowerCase();
+	return SUPPORTED_AUDIO_EXTENSIONS.has(ext);
+}
+
 function safeProjectId(raw: string): string {
 	// ponytail: project ids are uuid-prefixed strings (e.g. "proj_<uuid>"). Reject
 	// anything that smells like path traversal before we ever touch the disk.
@@ -283,7 +304,15 @@ export class DocumentService {
 		if (!input.path) {
 			throw new ProjectFileError("Asset path is required.", projectId);
 		}
-		if (!isSupportedVideoPath(input.path)) {
+		const kind = input.kind ?? "video";
+		if (kind === "audio") {
+			if (!isSupportedAudioPath(input.path)) {
+				throw new ProjectFileError(
+					`Unsupported audio extension: ${path.extname(input.path)} (supported: ${[...SUPPORTED_AUDIO_EXTENSIONS].join(", ")})`,
+					projectId,
+				);
+			}
+		} else if (!isSupportedVideoPath(input.path)) {
 			throw new ProjectFileError(
 				`Unsupported video extension: ${path.extname(input.path)} (supported: ${[...SUPPORTED_VIDEO_EXTENSIONS].join(", ")})`,
 				projectId,
@@ -300,18 +329,24 @@ export class DocumentService {
 		}
 		const asset: AxcutAsset = {
 			id: createId("asset"),
-			kind: "video",
+			kind,
 			label: input.label?.trim() || path.basename(absolutePath),
 			originalPath: absolutePath,
 			sizeBytes,
 			cameraTrack: null,
 		};
+		// An audio import is an overlay, never the thing the timeline is built
+		// around, so it must not claim the empty primaryAssetId slot — otherwise the
+		// first file dropped into a fresh project (a BGM track) would become its
+		// primary asset and the editor would try to lay out clips from a file with
+		// no video.
+		const claimsPrimary = kind !== "audio" && !doc.project.primaryAssetId;
 		const next: AxcutDocument = {
 			...doc,
 			assets: [...doc.assets, asset],
 			project: {
 				...doc.project,
-				...(doc.project.primaryAssetId ? {} : { primaryAssetId: asset.id }),
+				...(claimsPrimary ? { primaryAssetId: asset.id } : {}),
 				updatedAt: new Date().toISOString(),
 			},
 		};
diff --git a/electron/electron-env.d.ts b/electron/electron-env.d.ts
index 4eb288e14..852e76319 100644
--- a/electron/electron-env.d.ts
+++ b/electron/electron-env.d.ts
@@ -286,6 +286,14 @@ interface Window {
 			name?: string;
 			canceled?: boolean;
 		}>;
+		// Import an external audio file (voiceover / BGM / SFX) — issue #350.
+		openAudioFilePicker: () => Promise<{
+			success: boolean;
+			path?: string;
+			name?: string;
+			canceled?: boolean;
+			message?: string;
+		}>;
 		setCurrentVideoPath: (path: string) => Promise<{ success: boolean }>;
 		setCurrentRecordingSession: (
 			session: import("../src/lib/recordingSession").RecordingSession | null,
diff --git a/electron/ipc/handlers.ts b/electron/ipc/handlers.ts
index 958ef6d96..1edee583f 100644
--- a/electron/ipc/handlers.ts
+++ b/electron/ipc/handlers.ts
@@ -183,6 +183,23 @@ function hasAllowedImportVideoExtension(filePath: string): boolean {
 	return ALLOWED_IMPORT_VIDEO_EXTENSIONS.has(path.extname(filePath).toLowerCase());
 }
 
+// Imported audio (issue #350). Kept separate from the video set so the two
+// pickers stay honest — an audio picker must not approve a video path and vice
+// versa. Mirrors SUPPORTED_AUDIO_EXTENSIONS in the document service.
+const ALLOWED_IMPORT_AUDIO_EXTENSIONS = new Set([
+	".mp3",
+	".wav",
+	".m4a",
+	".aac",
+	".flac",
+	".ogg",
+	".opus",
+]);
+
+function hasAllowedImportAudioExtension(filePath: string): boolean {
+	return ALLOWED_IMPORT_AUDIO_EXTENSIONS.has(path.extname(filePath).toLowerCase());
+}
+
 function runProcess(
 	command: string,
 	args: string[],
@@ -279,8 +296,13 @@ async function prepareSupplementalPreviewAudioTrack(videoPath: string) {
 	return { success: true, path: pathToFileURL(outputPath).toString() };
 }
 
-async function approveReadableVideoPath(
-	filePath?: string | null,
+// Shared core behind the media path approvers. `hasAllowedExtension` is the ONLY
+// thing that differs between video and audio imports, so it is the single knob:
+// an already-approved path passes regardless, otherwise the extension gate,
+// optional trusted-dir confinement, and a stat check decide whether to approve.
+async function approveReadableMediaPath(
+	filePath: string | null | undefined,
+	hasAllowedExtension: (p: string) => boolean,
 	trustedDirs?: string[],
 ): Promise<string | null> {
 	const normalizedPath = normalizeVideoSourcePath(filePath);
@@ -292,7 +314,7 @@ async function approveReadableVideoPath(
 		return normalizedPath;
 	}
 
-	if (!hasAllowedImportVideoExtension(normalizedPath)) {
+	if (!hasAllowedExtension(normalizedPath)) {
 		return null;
 	}
 
@@ -319,6 +341,20 @@ async function approveReadableVideoPath(
 	return normalizedPath;
 }
 
+function approveReadableVideoPath(
+	filePath?: string | null,
+	trustedDirs?: string[],
+): Promise<string | null> {
+	return approveReadableMediaPath(filePath, hasAllowedImportVideoExtension, trustedDirs);
+}
+
+function approveReadableAudioPath(
+	filePath?: string | null,
+	trustedDirs?: string[],
+): Promise<string | null> {
+	return approveReadableMediaPath(filePath, hasAllowedImportAudioExtension, trustedDirs);
+}
+
 function resolveRecordingOutputPath(fileName: string): string {
 	const trimmed = fileName.trim();
 	if (!trimmed) {
@@ -3620,6 +3656,54 @@ export function registerIpcHandlers(
 		}
 	});
 
+	// Import an external audio file (voiceover / BGM / SFX) — issue #350. Mirrors
+	// the video picker but approves against the audio extension set; the returned
+	// path is added to the project as a `kind: "audio"` asset by the renderer.
+	ipcMain.handle("open-audio-file-picker", async () => {
+		try {
+			const dialogOptions = buildDialogOptions(
+				{
+					title: mainT("dialogs", "fileDialogs.selectAudio"),
+					defaultPath: RECORDINGS_DIR,
+					filters: [
+						{
+							name: mainT("dialogs", "fileDialogs.audioFiles"),
+							extensions: ["mp3", "wav", "m4a", "aac", "flac", "ogg", "opus"],
+						},
+						{ name: mainT("dialogs", "fileDialogs.allFiles"), extensions: ["*"] },
+					],
+					properties: ["openFile"],
+				},
+				getMainWindow(),
+			);
+			const result = await dialog.showOpenDialog(dialogOptions);
+
+			if (result.canceled || result.filePaths.length === 0) {
+				return { success: false, canceled: true };
+			}
+
+			const normalizedPath = await approveReadableAudioPath(result.filePaths[0]);
+			if (!normalizedPath) {
+				return {
+					success: false,
+					message: "Selected file is not a supported readable audio file",
+				};
+			}
+
+			return {
+				success: true,
+				path: normalizedPath,
+			};
+		} catch (error) {
+			console.error("Failed to open audio file picker:", error);
+			return {
+				success: false,
+				message: "Failed to open audio file picker",
+				error: String(error),
+			};
+		}
+	});
+
 	ipcMain.handle("reveal-in-folder", async (_, filePath: string) => {
 		try {
 			// showItemInFolder returns nothing, it throws on error
diff --git a/electron/ipc/nativeBridge.ts b/electron/ipc/nativeBridge.ts
index 47d66e270..884b50afd 100644
--- a/electron/ipc/nativeBridge.ts
+++ b/electron/ipc/nativeBridge.ts
@@ -483,6 +483,7 @@ export function registerNativeBridgeHandlers(context: NativeBridgeContext) {
 									request.payload.projectId,
 									request.payload.path,
 									request.payload.label,
+									request.payload.kind,
 								),
 							);
 						case "document.removeAsset":
diff --git a/electron/native-bridge/services/aiEditionService.ts b/electron/native-bridge/services/aiEditionService.ts
index 0fbbccc9c..90088781a 100644
--- a/electron/native-bridge/services/aiEditionService.ts
+++ b/electron/native-bridge/services/aiEditionService.ts
@@ -151,9 +151,17 @@ export class AiEditionService {
 		}
 	}
 
-	async addAsset(projectId: string, path: string, label?: string): Promise<AiEditionAssetResult> {
-		const document = await this.options.documents.addAsset(projectId, { path, label });
-		const assetId = document.project.primaryAssetId ?? document.assets.at(-1)?.id ?? "";
+	async addAsset(
+		projectId: string,
+		path: string,
+		label?: string,
+		kind?: "video" | "audio",
+	): Promise<AiEditionAssetResult> {
+		const document = await this.options.documents.addAsset(projectId, { path, label, kind });
+		// The just-added asset is always the last one; primaryAssetId is only a
+		// fallback for the video case and would point at the wrong asset for an
+		// audio import (which never claims primary), so prefer the tail.
+		const assetId = document.assets.at(-1)?.id ?? document.project.primaryAssetId ?? "";
 		return { assetId, document };
 	}
 
diff --git a/electron/preload.ts b/electron/preload.ts
index 6aff16407..16227f110 100644
--- a/electron/preload.ts
+++ b/electron/preload.ts
@@ -276,6 +276,9 @@ contextBridge.exposeInMainWorld("electronAPI", {
 	openVideoFilePicker: () => {
 		return ipcRenderer.invoke("open-video-file-picker");
 	},
+	openAudioFilePicker: () => {
+		return ipcRenderer.invoke("open-audio-file-picker");
+	},
 	setCurrentVideoPath: (path: string) => {
 		return ipcRenderer.invoke("set-current-video-path", path);
 	},
diff --git a/src/i18n/locales/ar/dialogs.json b/src/i18n/locales/ar/dialogs.json
index 43caf5938..1032d22cb 100644
--- a/src/i18n/locales/ar/dialogs.json
+++ b/src/i18n/locales/ar/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "حفظ GIF المصدر",
 		"saveVideo": "حفظ الفيديو المصدر",
 		"selectVideo": "حدد ملف فيديو",
+		"selectAudio": "Select Audio File",
 		"saveProject": "حفظ مشروع OpenScreen",
 		"openProject": "فتح مشروع OpenScreen",
 		"gifImage": "صورة GIF",
 		"mp4Video": "فيديو MP4",
 		"videoFiles": "ملفات فيديو",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "مشروع OpenScreen",
 		"allFiles": "جميع الملفات"
 	}
diff --git a/src/i18n/locales/en/dialogs.json b/src/i18n/locales/en/dialogs.json
index 90599af16..3d898d1a2 100644
--- a/src/i18n/locales/en/dialogs.json
+++ b/src/i18n/locales/en/dialogs.json
@@ -80,11 +80,13 @@
 		"saveGif": "Save Exported GIF",
 		"saveVideo": "Save Exported Video",
 		"selectVideo": "Select Video File",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Save OpenScreen Project",
 		"openProject": "Open OpenScreen Project",
 		"gifImage": "GIF Image",
 		"mp4Video": "MP4 Video",
 		"videoFiles": "Video Files",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "OpenScreen Project",
 		"allFiles": "All Files"
 	}
diff --git a/src/i18n/locales/es/dialogs.json b/src/i18n/locales/es/dialogs.json
index 954121938..10ebb2315 100644
--- a/src/i18n/locales/es/dialogs.json
+++ b/src/i18n/locales/es/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "Guardar GIF exportado",
 		"saveVideo": "Guardar video exportado",
 		"selectVideo": "Seleccionar archivo de video",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Guardar proyecto OpenScreen",
 		"openProject": "Abrir proyecto OpenScreen",
 		"gifImage": "Imagen GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "Archivos de video",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "Proyecto OpenScreen",
 		"allFiles": "Todos los archivos"
 	}
diff --git a/src/i18n/locales/fr/dialogs.json b/src/i18n/locales/fr/dialogs.json
index 82fc95dcb..a7691550e 100644
--- a/src/i18n/locales/fr/dialogs.json
+++ b/src/i18n/locales/fr/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "Enregistrer le GIF exporté",
 		"saveVideo": "Enregistrer la vidéo exportée",
 		"selectVideo": "Sélectionner un fichier vidéo",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Enregistrer le projet OpenScreen",
 		"openProject": "Ouvrir un projet OpenScreen",
 		"gifImage": "Image GIF",
 		"mp4Video": "Vidéo MP4",
 		"videoFiles": "Fichiers vidéo",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "Projet OpenScreen",
 		"allFiles": "Tous les fichiers"
 	}
diff --git a/src/i18n/locales/it/dialogs.json b/src/i18n/locales/it/dialogs.json
index 0fad7d36e..b26a83da9 100644
--- a/src/i18n/locales/it/dialogs.json
+++ b/src/i18n/locales/it/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "Salva GIF esportata",
 		"saveVideo": "Salva video esportato",
 		"selectVideo": "Seleziona file video",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Salva progetto OpenScreen",
 		"openProject": "Apri progetto OpenScreen",
 		"gifImage": "Immagine GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "File video",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "Progetto OpenScreen",
 		"allFiles": "Tutti i file"
 	}
diff --git a/src/i18n/locales/ja-JP/dialogs.json b/src/i18n/locales/ja-JP/dialogs.json
index 7ee976a77..911c2ad94 100644
--- a/src/i18n/locales/ja-JP/dialogs.json
+++ b/src/i18n/locales/ja-JP/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "エクスポートしたGIFを保存",
 		"saveVideo": "エクスポートした動画を保存",
 		"selectVideo": "動画ファイルを選択",
+		"selectAudio": "Select Audio File",
 		"saveProject": "OpenScreen プロジェクトを保存",
 		"openProject": "OpenScreen プロジェクトを開く",
 		"gifImage": "GIF 画像",
 		"mp4Video": "MP4 動画",
 		"videoFiles": "動画ファイル",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "OpenScreen プロジェクト",
 		"allFiles": "すべてのファイル"
 	}
diff --git a/src/i18n/locales/ko-KR/dialogs.json b/src/i18n/locales/ko-KR/dialogs.json
index 5891f44c1..d654a5f52 100644
--- a/src/i18n/locales/ko-KR/dialogs.json
+++ b/src/i18n/locales/ko-KR/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "내보낸 GIF 저장",
 		"saveVideo": "내보낸 비디오 저장",
 		"selectVideo": "비디오 파일 선택",
+		"selectAudio": "Select Audio File",
 		"saveProject": "OpenScreen 프로젝트 저장",
 		"openProject": "OpenScreen 프로젝트 열기",
 		"gifImage": "GIF 이미지",
 		"mp4Video": "MP4 비디오",
 		"videoFiles": "비디오 파일",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "OpenScreen 프로젝트",
 		"allFiles": "모든 파일"
 	}
diff --git a/src/i18n/locales/pt-BR/dialogs.json b/src/i18n/locales/pt-BR/dialogs.json
index ba77d90a9..7dbb4c642 100644
--- a/src/i18n/locales/pt-BR/dialogs.json
+++ b/src/i18n/locales/pt-BR/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "Salvar GIF Exportado",
 		"saveVideo": "Salvar Vídeo Exportado",
 		"selectVideo": "Selecionar Arquivo de Vídeo",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Salvar Projeto OpenScreen",
 		"openProject": "Abrir Projeto OpenScreen",
 		"gifImage": "Imagem GIF",
 		"mp4Video": "Vídeo MP4",
 		"videoFiles": "Arquivos de Vídeo",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "Projeto OpenScreen",
 		"allFiles": "Todos os Arquivos"
 	}
diff --git a/src/i18n/locales/ru/dialogs.json b/src/i18n/locales/ru/dialogs.json
index a821771e9..7e1dbaeed 100644
--- a/src/i18n/locales/ru/dialogs.json
+++ b/src/i18n/locales/ru/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "Сохранить экспортированный GIF",
 		"saveVideo": "Сохранить экспортированное видео",
 		"selectVideo": "Выбрать видеофайл",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Сохранить проект OpenScreen",
 		"openProject": "Открыть проект OpenScreen",
 		"gifImage": "GIF изображение",
 		"mp4Video": "MP4 видео",
 		"videoFiles": "Видеофайлы",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "Проект OpenScreen",
 		"allFiles": "Все файлы"
 	}
diff --git a/src/i18n/locales/tr/dialogs.json b/src/i18n/locales/tr/dialogs.json
index 196807fd3..c6299d520 100644
--- a/src/i18n/locales/tr/dialogs.json
+++ b/src/i18n/locales/tr/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "Dışa Aktarılan GIF'i Kaydet",
 		"saveVideo": "Dışa Aktarılan Videoyu Kaydet",
 		"selectVideo": "Video Dosyası Seç",
+		"selectAudio": "Select Audio File",
 		"saveProject": "OpenScreen Projesini Kaydet",
 		"openProject": "OpenScreen Projesini Aç",
 		"gifImage": "GIF Görüntüsü",
 		"mp4Video": "MP4 Video",
 		"videoFiles": "Video Dosyaları",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "OpenScreen Projesi",
 		"allFiles": "Tüm Dosyalar"
 	}
diff --git a/src/i18n/locales/vi/dialogs.json b/src/i18n/locales/vi/dialogs.json
index 644d2ba02..213240763 100644
--- a/src/i18n/locales/vi/dialogs.json
+++ b/src/i18n/locales/vi/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "Lưu GIF đã xuất",
 		"saveVideo": "Lưu Video đã xuất",
 		"selectVideo": "Chọn tệp video",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Lưu dự án OpenScreen",
 		"openProject": "Mở dự án OpenScreen",
 		"gifImage": "Hình ảnh GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "Tệp Video",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "Dự án OpenScreen",
 		"allFiles": "Tất cả các tệp"
 	}
diff --git a/src/i18n/locales/zh-CN/dialogs.json b/src/i18n/locales/zh-CN/dialogs.json
index 645ebf9d8..b28304f6c 100644
--- a/src/i18n/locales/zh-CN/dialogs.json
+++ b/src/i18n/locales/zh-CN/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "保存导出的 GIF",
 		"saveVideo": "保存导出的视频",
 		"selectVideo": "选择视频文件",
+		"selectAudio": "Select Audio File",
 		"saveProject": "保存 OpenScreen 项目",
 		"openProject": "打开 OpenScreen 项目",
 		"gifImage": "GIF 图片",
 		"mp4Video": "MP4 视频",
 		"videoFiles": "视频文件",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "OpenScreen 项目",
 		"allFiles": "所有文件"
 	}
diff --git a/src/i18n/locales/zh-TW/dialogs.json b/src/i18n/locales/zh-TW/dialogs.json
index 14fc364a0..6c3601511 100644
--- a/src/i18n/locales/zh-TW/dialogs.json
+++ b/src/i18n/locales/zh-TW/dialogs.json
@@ -79,11 +79,13 @@
 		"saveGif": "儲存匯出的 GIF",
 		"saveVideo": "儲存匯出的影片",
 		"selectVideo": "選擇影片檔案",
+		"selectAudio": "Select Audio File",
 		"saveProject": "儲存 OpenScreen 專案",
 		"openProject": "開啟 OpenScreen 專案",
 		"gifImage": "GIF 圖片",
 		"mp4Video": "MP4 影片",
 		"videoFiles": "影片檔案",
+		"audioFiles": "Audio Files",
 		"openscreenProject": "OpenScreen 專案",
 		"allFiles": "所有檔案"
 	}
diff --git a/src/lib/ai-edition/schema/index.ts b/src/lib/ai-edition/schema/index.ts
index a6efe746b..7024b37c4 100644
--- a/src/lib/ai-edition/schema/index.ts
+++ b/src/lib/ai-edition/schema/index.ts
@@ -843,6 +843,10 @@ export const createProjectInputSchema = z.object({
 export const addAssetInputSchema = z.object({
 	path: z.string().trim().min(1),
 	label: z.string().trim().optional(),
+	// "audio" imports an external voiceover / BGM / SFX file (issue #350); it has
+	// no video stream and never becomes the project's primary asset. Defaults to
+	// "video" so every existing caller keeps its current behaviour.
+	kind: z.enum(["video", "audio"]).default("video"),
 	autoTranscribe: z.boolean().default(true),
 });
 
diff --git a/src/lib/ai-edition/store/projectStore.test.ts b/src/lib/ai-edition/store/projectStore.test.ts
index 84074aad2..0c920be7a 100644
--- a/src/lib/ai-edition/store/projectStore.test.ts
+++ b/src/lib/ai-edition/store/projectStore.test.ts
@@ -16,6 +16,17 @@ const toastMocks = vi.hoisted(() => ({
 	error: vi.fn(),
 }));
 
+// Stub only the audio duration probe (issue #350): mounting a real <audio> in
+// jsdom never fires loadedmetadata, so an unmocked probe would block on its
+// timeout. Everything else in the module (probeVideoDimensions) stays real so
+// the video-import tests above are untouched.
+const durationMocks = vi.hoisted(() => ({ probeAudioDuration: vi.fn() }));
+
+vi.mock("../timeline/duration", async (importOriginal) => ({
+	...(await importOriginal<typeof import("../timeline/duration")>()),
+	probeAudioDuration: durationMocks.probeAudioDuration,
+}));
+
 vi.mock("@/native/client", () => ({
 	nativeBridgeClient: {
 		aiEdition: {
@@ -73,6 +84,7 @@ describe("useProjectStore", () => {
 			mock.mockReset();
 		}
 		toastMocks.error.mockReset();
+		durationMocks.probeAudioDuration.mockReset();
 		// biome-ignore lint/suspicious/noExplicitAny: test-only stub of the legacy contextBridge surface
 		(window as any).electronAPI = { findRecordingCamera: vi.fn() };
 	});
@@ -299,6 +311,69 @@ describe("useProjectStore", () => {
 		expect(toastMocks.error.mock.calls[0][0]).toContain("video.mp4");
 	});
 
+	// Issue #350 — external audio import.
+	it("addAudioAsset passes kind 'audio', skips the camera lookup, and returns the asset", async () => {
+		useProjectStore.setState({
+			projectId: "proj_test",
+			document: sampleDoc,
+			revision: 1,
+			status: "ready",
+			error: null,
+		});
+		durationMocks.probeAudioDuration.mockResolvedValue(null);
+		const audioDoc = {
+			...sampleDoc,
+			assets: [
+				{ id: "audio_asset", kind: "audio", label: "voiceover.mp3", originalPath: "/tmp/vo.mp3" },
+			],
+		};
+		bridgeMocks.addAsset.mockResolvedValue({ assetId: "audio_asset", document: audioDoc });
+
+		const asset = await useProjectStore.getState().addAudioAsset("/tmp/vo.mp3");
+
+		expect(asset?.id).toBe("audio_asset");
+		expect(asset?.kind).toBe("audio");
+		// The bridge must be told this is an audio import (4th arg).
+		expect(bridgeMocks.addAsset).toHaveBeenCalledWith(
+			"proj_test",
+			"/tmp/vo.mp3",
+			undefined,
+			"audio",
+		);
+		// Audio has no camera sidecar — the lookup that addAsset does must not run.
+		// biome-ignore lint/suspicious/noExplicitAny: test-only stub of the legacy contextBridge surface
+		expect((window as any).electronAPI.findRecordingCamera).not.toHaveBeenCalled();
+		// Probe returned null, so nothing to stamp: no extra save.
+		expect(bridgeMocks.save).not.toHaveBeenCalled();
+	});
+
+	it("addAudioAsset stamps the probed duration onto the asset", async () => {
+		useProjectStore.setState({
+			projectId: "proj_test",
+			document: sampleDoc,
+			revision: 1,
+			status: "ready",
+			error: null,
+		});
+		durationMocks.probeAudioDuration.mockResolvedValue(8.25);
+		const audioDoc = {
+			...sampleDoc,
+			assets: [
+				{ id: "audio_asset", kind: "audio", label: "bgm.wav", originalPath: "/tmp/bgm.wav" },
+			],
+		};
+		bridgeMocks.addAsset.mockResolvedValue({ assetId: "audio_asset", document: audioDoc });
+		bridgeMocks.save.mockImplementation((document: unknown) =>
+			Promise.resolve({ success: true, document }),
+		);
+
+		const asset = await useProjectStore.getState().addAudioAsset("/tmp/bgm.wav");
+
+		expect(asset?.durationSec).toBe(8.25);
+		expect(bridgeMocks.save).toHaveBeenCalledTimes(1);
+		expect(useProjectStore.getState().document?.assets[0]?.durationSec).toBe(8.25);
+	});
+
 	// The save boundary. Every write in the app funnels through `saveDocument`, and
 	// almost every caller `void`s it from a click handler, so what this function does
 	// with a failure IS what the user sees.
diff --git a/src/lib/ai-edition/store/projectStore.ts b/src/lib/ai-edition/store/projectStore.ts
index 48dad73e2..4d2eeb30c 100644
--- a/src/lib/ai-edition/store/projectStore.ts
+++ b/src/lib/ai-edition/store/projectStore.ts
@@ -5,7 +5,7 @@ import { toastText } from "@/i18n/toastText";
 import { nativeBridgeClient } from "@/native/client";
 import { type Interval, replaceTimeline as replaceTimelineOp } from "../document/timeline";
 import { type AxcutAsset, type AxcutDocument, documentSchema } from "../schema";
-import { probeVideoDimensions } from "../timeline/duration";
+import { probeAudioDuration, probeVideoDimensions } from "../timeline/duration";
 import { clearHistory, currentWriteEpoch, pushHistory } from "./undoStack";
 
 // ponytail: thin Zustand wrapper over the native-bridge client. Keeps the
@@ -72,6 +72,14 @@ export interface ProjectState {
 	createProject: (title: string) => Promise<AxcutDocument>;
 	refresh: () => Promise<void>;
 	addAsset: (path: string, label?: string) => Promise<AxcutAsset | null>;
+	/**
+	 * Import an external audio file (voiceover / BGM / SFX) as a `kind: "audio"`
+	 * asset — issue #350. Unlike {@link addAsset} it never looks for a camera
+	 * sidecar, and it probes the file's duration up front so the timeline can lay
+	 * out its track (added separately, see the timeline store). Returns the added
+	 * asset, or null if the write was superseded.
+	 */
+	addAudioAsset: (path: string, label?: string) => Promise<AxcutAsset | null>;
 	removeAsset: (assetId: string) => Promise<void>;
 	/**
 	 * Write the document to disk. Resolves `true` when it took effect, `false` when it
@@ -325,6 +333,51 @@ export const useProjectStore = create<ProjectState>((set, get) => ({
 		return addedAsset;
 	},
 
+	async addAudioAsset(path, label) {
+		const { projectId } = get();
+		if (!projectId) throw new Error("No project loaded");
+		// Same superseded guard as addAsset: the native add, a duration probe and a
+		// save all await, and a project switch / clear can land in between.
+		const epoch = currentWriteEpoch();
+		const superseded = () => get().projectId !== projectId || currentWriteEpoch() !== epoch;
+		const result = await nativeBridgeClient.aiEdition.addAsset(projectId, path, label, "audio");
+		if (superseded()) return null;
+		let document = parseDocument(result.document);
+		const addedAsset =
+			document.assets.find(
+				(a) => a.kind === "audio" && a.originalPath === path && (label ? a.label === label : true),
+			) ??
+			document.assets.at(-1) ??
+			null;
+		if (!addedAsset) return null;
+
+		// Probe the real length so the timeline can size the track pill immediately
+		// on add. Non-fatal: an unreadable file just leaves durationSec unset and the
+		// track store falls back to a placeholder. No camera lookup — audio has none.
+		const durationSec = await probeAudioDuration(toFileUrl(addedAsset.originalPath)).catch(
+			() => null,
+		);
+		if (superseded()) return null;
+		if (durationSec != null) {
+			const next: AxcutDocument = {
+				...document,
+				assets: document.assets.map((a) => (a.id === addedAsset.id ? { ...a, durationSec } : a)),
+			};
+			// history: false — probing a duration is part of the import, not an edit
+			// of its own, so it must not become the thing the next Ctrl+Z reverses.
+			if (await get().saveDocument(next, { history: false })) document = parseDocument(next);
+		}
+
+		if (superseded()) return null;
+		set({
+			document,
+			revision: get().revision + 1,
+			dirty: false,
+			lastSavedAt: new Date(),
+		});
+		return document.assets.find((a) => a.id === addedAsset.id) ?? addedAsset;
+	},
+
 	async removeAsset(assetId) {
 		const { projectId } = get();
 		if (!projectId) throw new Error("No project loaded");
diff --git a/src/lib/ai-edition/timeline/duration.test.ts b/src/lib/ai-edition/timeline/duration.test.ts
index 528c3b910..ccc41cb5a 100644
--- a/src/lib/ai-edition/timeline/duration.test.ts
+++ b/src/lib/ai-edition/timeline/duration.test.ts
@@ -1,6 +1,6 @@
 // @vitest-environment jsdom
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
-import { probeVideoDuration } from "./duration";
+import { probeAudioDuration, probeVideoDuration } from "./duration";
 
 interface FakeVideo {
 	duration: number;
@@ -8,7 +8,16 @@ interface FakeVideo {
 	onerror: ((ev: Event) => unknown) | null;
 }
 
-describe("probeVideoDuration", () => {
+// `probeVideoDuration` and `probeAudioDuration` are the same probe on a
+// different media element, so the fake-element harness and the cases are shared
+// and driven per tag. See the schema/store for why audio import needs its own
+// probe (issue #350).
+const PROBES = [
+	{ label: "probeVideoDuration", tag: "video", probe: probeVideoDuration },
+	{ label: "probeAudioDuration", tag: "audio", probe: probeAudioDuration },
+] as const;
+
+describe.each(PROBES)("$label", ({ tag, probe }) => {
 	let created: FakeVideo[];
 	let originalCreate: typeof document.createElement;
 	let appendSpy: ReturnType<typeof vi.spyOn> | null;
@@ -21,9 +30,9 @@ describe("probeVideoDuration", () => {
 		// `"webview"`-only overload — the one `.call` resolves to, which then rejects a
 		// generic string tag. Pin the plain `(tagName: string) => HTMLElement` overload.
 		const createReal: (this: Document, tag: string) => HTMLElement = originalCreate;
-		document.createElement = ((tag: string) => {
-			const node = createReal.call(document, tag);
-			if (tag === "video") {
+		document.createElement = ((el: string) => {
+			const node = createReal.call(document, el);
+			if (el === tag) {
 				const fake: FakeVideo = {
 					duration: Number.NaN,
 					onloadedmetadata: null,
@@ -66,11 +75,11 @@ describe("probeVideoDuration", () => {
 	});
 
 	it("returns null when src is empty", async () => {
-		await expect(probeVideoDuration("")).resolves.toBeNull();
+		await expect(probe("")).resolves.toBeNull();
 	});
 
 	it("returns duration on loadedmetadata", async () => {
-		const p = probeVideoDuration("file:///tmp/clip.mp4");
+		const p = probe("file:///tmp/clip");
 		await vi.advanceTimersByTimeAsync(0);
 		const v = created[0];
 		v.duration = 12.5;
@@ -79,14 +88,14 @@ describe("probeVideoDuration", () => {
 	});
 
 	it("returns null on error", async () => {
-		const p = probeVideoDuration("file:///missing.mp4");
+		const p = probe("file:///missing");
 		await vi.advanceTimersByTimeAsync(0);
 		created[0].onerror?.(new Event("error"));
 		await expect(p).resolves.toBeNull();
 	});
 
 	it("returns null on timeout", async () => {
-		const p = probeVideoDuration("file:///slow.mp4", 1000);
+		const p = probe("file:///slow", 1000);
 		await vi.advanceTimersByTimeAsync(0);
 		await vi.advanceTimersByTimeAsync(2000);
 		await expect(p).resolves.toBeNull();
@@ -94,7 +103,7 @@ describe("probeVideoDuration", () => {
 
 	it("returns null for non-finite duration", async () => {
 		for (const d of [Number.POSITIVE_INFINITY, Number.NaN, -1, 0]) {
-			const p = probeVideoDuration("file:///x.mp4");
+			const p = probe("file:///x");
 			await vi.advanceTimersByTimeAsync(0);
 			const v = created[created.length - 1];
 			v.duration = d;
diff --git a/src/lib/ai-edition/timeline/duration.ts b/src/lib/ai-edition/timeline/duration.ts
index 950d2ae3b..87d01ab11 100644
--- a/src/lib/ai-edition/timeline/duration.ts
+++ b/src/lib/ai-edition/timeline/duration.ts
@@ -62,6 +62,64 @@ export function probeVideoDuration(
 	});
 }
 
+/**
+ * Duration of an imported audio file (issue #350), probed by mounting a hidden
+ * <audio> and waiting for loadedmetadata — the audio-only counterpart of
+ * `probeVideoDuration`. Used when an external voiceover / BGM / SFX file is added
+ * so the timeline can size its track pill at the real length immediately.
+ *
+ * Falls back to null on error / timeout / non-finite duration, exactly like the
+ * video probe; the caller decides whether to retry or use a placeholder.
+ */
+export function probeAudioDuration(
+	src: string,
+	timeoutMs: number = DEFAULT_TIMEOUT_MS,
+): Promise<number | null> {
+	return new Promise((resolve) => {
+		if (typeof document === "undefined" || !src) {
+			resolve(null);
+			return;
+		}
+		const audio = document.createElement("audio");
+		audio.preload = "metadata";
+		audio.style.position = "absolute";
+		audio.style.width = "1px";
+		audio.style.height = "1px";
+		audio.style.opacity = "0";
+		audio.style.pointerEvents = "none";
+		audio.style.left = "-9999px";
+		let settled = false;
+		const cleanup = () => {
+			audio.onloadedmetadata = null;
+			audio.onerror = null;
+			clearTimeout(timer);
+			try {
+				audio.removeAttribute("src");
+				audio.load();
+			} catch {
+				// ignore — browser may refuse if already detached
+			}
+			if (audio.parentNode) audio.parentNode.removeChild(audio);
+		};
+		const settle = (value: number | null) => {
+			if (settled) return;
+			settled = true;
+			cleanup();
+			resolve(value);
+		};
+		const timer = setTimeout(() => settle(null), timeoutMs);
+		audio.onloadedmetadata = () => {
+			const d = audio.duration;
+			settle(Number.isFinite(d) && d > 0 ? d : null);
+		};
+		audio.onerror = () => settle(null);
+		// Append to body so some browsers (Firefox) fire loadedmetadata for an
+		// otherwise-detached media element — same reason as the video probe.
+		document.body.appendChild(audio);
+		audio.src = src;
+	});
+}
+
 /** Native pixel dimensions, same probe shape as `probeVideoDuration` (separate DOM element —
  *  cheap, one-shot, not worth merging into a combined probe for the one extra caller that
  *  needs both). `asset.video` was otherwise left permanently unset for most recordings (nothing
diff --git a/src/native/browserShim.ts b/src/native/browserShim.ts
index c00f53d51..c9e5d395b 100644
--- a/src/native/browserShim.ts
+++ b/src/native/browserShim.ts
@@ -186,7 +186,7 @@ function createShimBridgeClient() {
 			updatedAt: string;
 			primaryAssetId?: string;
 		};
-		assets: Array<{ id: string; kind: "video"; label: string; originalPath: string }>;
+		assets: Array<{ id: string; kind: "video" | "audio"; label: string; originalPath: string }>;
 		[key: string]: unknown;
 	};
 	const projectsStorageKey = "browser-shim-projects-v2";
@@ -408,20 +408,27 @@ function createShimBridgeClient() {
 				saveProjectsState();
 				return Promise.resolve({ success: true });
 			},
-			addAsset: (projectId: string, path: string, label?: string) => {
+			addAsset: (projectId: string, path: string, label?: string, kind?: "video" | "audio") => {
 				const doc = documentsByProject[projectId];
 				if (!doc) return Promise.resolve({ assetId: "", document: null });
 				const assetId = `asset_${Math.random().toString(36).slice(2, 10)}`;
+				const assetKind = kind ?? "video";
 				const asset = {
 					id: assetId,
-					kind: "video" as const,
+					kind: assetKind,
 					label: label || path.split(/[\\/]/).pop() || "Recording",
 					originalPath: path,
 				};
+				// Mirror the main-process rule: an audio import never claims the empty
+				// primary slot (see document-service.addAsset).
+				const claimsPrimary = assetKind !== "audio" && !doc.project.primaryAssetId;
 				const next: ShimDocument = {
 					...doc,
 					assets: [...doc.assets, asset],
-					project: { ...doc.project, primaryAssetId: doc.project.primaryAssetId ?? assetId },
+					project: {
+						...doc.project,
+						primaryAssetId: claimsPrimary ? assetId : doc.project.primaryAssetId,
+					},
 				};
 				documentsByProject[projectId] = next;
 				saveProjectsState();
diff --git a/src/native/client.ts b/src/native/client.ts
index eed5d68d7..fce40fa6c 100644
--- a/src/native/client.ts
+++ b/src/native/client.ts
@@ -181,11 +181,11 @@ export const nativeBridgeClient = {
 				action: "document.delete",
 				payload: { projectId },
 			}),
-		addAsset: (projectId: string, path: string, label?: string) =>
+		addAsset: (projectId: string, path: string, label?: string, kind?: "video" | "audio") =>
 			requireNativeBridgeData<AiEditionAssetResult>({
 				domain: "aiEdition",
 				action: "document.addAsset",
-				payload: { projectId, path, label },
+				payload: { projectId, path, label, kind },
 			}),
 		removeAsset: (projectId: string, assetId: string) =>
 			requireNativeBridgeData<AiEditionAssetResult>({
diff --git a/src/native/contracts.ts b/src/native/contracts.ts
index ede052f32..7cd15b1f7 100644
--- a/src/native/contracts.ts
+++ b/src/native/contracts.ts
@@ -516,7 +516,7 @@ export type NativeBridgeRequest =
 	| {
 			domain: "aiEdition";
 			action: "document.addAsset";
-			payload: { projectId: string; path: string; label?: string };
+			payload: { projectId: string; path: string; label?: string; kind?: "video" | "audio" };
 			requestId?: string;
 	  }
 	| {

From 255b9f2acf23a8d816e340d72515809861603ae0 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Mon, 24 Aug 2026 23:33:22 +0200
Subject: [PATCH 03/20] feat(editor): add timeline state ops for imported audio
 tracks
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Phase 3 of issue #350. Adds the mutations that place and edit imported
audio tracks on the timeline. Still no UI or preview/export — that's next.

- New pure module document/audioTracks.ts: append / remove / move / trim /
  gain / mute, each taking an AxcutDocument and returning a new one. Audio
  tracks aren't clip-anchored (they float over the assembled programme in
  output-timeline seconds), so these are plain array edits with schema-valid
  guards — negatives floored, trimEnd pulled up to trimStart, NaN → 0.
- useTimeline wraps them: addAudioTrack looks up the audio asset, places the
  head at the playhead (output time) by default, and returns the new track id
  for the UI to select; move/resize/gain/mute/remove each commit one history
  step. Refuses a non-audio or unknown asset.
- Tests: the pure ops (immutability, guards, isolation) and the hook wiring
  (asset lookup, playhead placement, save, undo).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 .../ai-edition/document/audioTracks.test.ts   |  78 ++++++++++++
 src/lib/ai-edition/document/audioTracks.ts    |  87 +++++++++++++
 src/lib/ai-edition/store/useTimeline.test.ts  | 119 ++++++++++++++++++
 src/lib/ai-edition/store/useTimeline.ts       |  92 +++++++++++++-
 4 files changed, 375 insertions(+), 1 deletion(-)
 create mode 100644 src/lib/ai-edition/document/audioTracks.test.ts
 create mode 100644 src/lib/ai-edition/document/audioTracks.ts

diff --git a/src/lib/ai-edition/document/audioTracks.test.ts b/src/lib/ai-edition/document/audioTracks.test.ts
new file mode 100644
index 000000000..58333dd5d
--- /dev/null
+++ b/src/lib/ai-edition/document/audioTracks.test.ts
@@ -0,0 +1,78 @@
+import { describe, expect, it } from "vitest";
+import { createAudioTrack, createEmptyDocument } from "../schema";
+import {
+	appendAudioTrack,
+	moveAudioTrack,
+	removeAudioTrack,
+	setAudioTrackGain,
+	setAudioTrackMute,
+	setAudioTrackTrim,
+} from "./audioTracks";
+
+const emptyDoc = () => createEmptyDocument({ projectId: "p", title: "t" });
+
+const docWithTrack = () => {
+	const track = createAudioTrack({ assetId: "asset_1", durationSec: 30, timelineStartSec: 5 });
+	return { doc: appendAudioTrack(emptyDoc(), track), track };
+};
+
+describe("audioTracks document ops (issue #350)", () => {
+	it("appendAudioTrack adds the track without mutating the input", () => {
+		const doc = emptyDoc();
+		const track = createAudioTrack({ assetId: "asset_1", durationSec: 12 });
+		const next = appendAudioTrack(doc, track);
+		expect(next.audioTracks).toEqual([track]);
+		expect(doc.audioTracks).toEqual([]);
+	});
+
+	it("removeAudioTrack drops the matching track and is a no-op for unknown ids", () => {
+		const { doc, track } = docWithTrack();
+		expect(removeAudioTrack(doc, track.id).audioTracks).toEqual([]);
+		expect(removeAudioTrack(doc, "nope").audioTracks).toEqual([track]);
+	});
+
+	it("moveAudioTrack repositions the head and floors negatives at 0", () => {
+		const { doc, track } = docWithTrack();
+		expect(moveAudioTrack(doc, track.id, 9).audioTracks[0]?.timelineStartSec).toBe(9);
+		expect(moveAudioTrack(doc, track.id, -4).audioTracks[0]?.timelineStartSec).toBe(0);
+		expect(moveAudioTrack(doc, track.id, Number.NaN).audioTracks[0]?.timelineStartSec).toBe(0);
+	});
+
+	it("setAudioTrackTrim keeps trimEnd >= trimStart so the result stays schema-valid", () => {
+		const { doc, track } = docWithTrack();
+		const trimmed = setAudioTrackTrim(doc, track.id, { trimStartSec: 4, trimEndSec: 2 });
+		expect(trimmed.audioTracks[0]?.trimStartSec).toBe(4);
+		// trimEnd was pulled up to trimStart rather than left below it.
+		expect(trimmed.audioTracks[0]?.trimEndSec).toBe(4);
+	});
+
+	it("setAudioTrackTrim clears the tail trim when trimEndSec is undefined", () => {
+		const { doc, track } = docWithTrack();
+		const withTail = setAudioTrackTrim(doc, track.id, { trimStartSec: 1, trimEndSec: 10 });
+		const cleared = setAudioTrackTrim(withTail, track.id, { trimStartSec: 1 });
+		expect(cleared.audioTracks[0]?.trimEndSec).toBeUndefined();
+	});
+
+	it("setAudioTrackGain stores a finite dB and defaults NaN to 0", () => {
+		const { doc, track } = docWithTrack();
+		expect(setAudioTrackGain(doc, track.id, -6).audioTracks[0]?.gainDb).toBe(-6);
+		expect(setAudioTrackGain(doc, track.id, Number.NaN).audioTracks[0]?.gainDb).toBe(0);
+	});
+
+	it("setAudioTrackMute toggles mute without touching gain", () => {
+		const { doc, track } = docWithTrack();
+		const withGain = setAudioTrackGain(doc, track.id, -3);
+		const muted = setAudioTrackMute(withGain, track.id, true);
+		expect(muted.audioTracks[0]?.mute).toBe(true);
+		expect(muted.audioTracks[0]?.gainDb).toBe(-3);
+	});
+
+	it("update ops leave other tracks untouched", () => {
+		const a = createAudioTrack({ assetId: "asset_1", durationSec: 10 });
+		const b = createAudioTrack({ assetId: "asset_2", durationSec: 20 });
+		const doc = appendAudioTrack(appendAudioTrack(emptyDoc(), a), b);
+		const next = moveAudioTrack(doc, b.id, 7);
+		expect(next.audioTracks[0]).toEqual(a);
+		expect(next.audioTracks[1]?.timelineStartSec).toBe(7);
+	});
+});
diff --git a/src/lib/ai-edition/document/audioTracks.ts b/src/lib/ai-edition/document/audioTracks.ts
new file mode 100644
index 000000000..b00608c45
--- /dev/null
+++ b/src/lib/ai-edition/document/audioTracks.ts
@@ -0,0 +1,87 @@
+// Pure document operations for imported audio tracks (issue #350). No DOM, no
+// IPC: each function takes an AxcutDocument and returns a new one with
+// `audioTracks` updated. The store (useTimeline) wraps these with saveDocument;
+// the schema factory (createAudioTrack) builds the track the append receives.
+//
+// Audio tracks are NOT clip-anchored — they float over the assembled programme
+// in OUTPUT (post-trim/post-speed) timeline seconds — so unlike clip regions
+// these ops need no anchoring, just array edits with schema-valid guards.
+
+import type { AxcutAudioTrack, AxcutDocument } from "../schema";
+
+// Timeline values arrive from drag deltas and persisted documents, both of which
+// can carry NaN; every op clamps the same way the region ops in useTimeline do.
+const finiteNonNeg = (n: number) => (Number.isFinite(n) ? Math.max(0, n) : 0);
+const finite = (n: number) => (Number.isFinite(n) ? n : 0);
+
+/** Append a track (built by `createAudioTrack`) to the document. */
+export function appendAudioTrack(doc: AxcutDocument, track: AxcutAudioTrack): AxcutDocument {
+	return { ...doc, audioTracks: [...doc.audioTracks, track] };
+}
+
+/** Drop a track by id. A no-op if the id isn't present. */
+export function removeAudioTrack(doc: AxcutDocument, trackId: string): AxcutDocument {
+	return { ...doc, audioTracks: doc.audioTracks.filter((t) => t.id !== trackId) };
+}
+
+// Shared updater — maps the one matching track through `patch`. Keeps every op
+// below a single expression and the "not found" case a clean no-op.
+function updateAudioTrack(
+	doc: AxcutDocument,
+	trackId: string,
+	patch: (track: AxcutAudioTrack) => AxcutAudioTrack,
+): AxcutDocument {
+	return {
+		...doc,
+		audioTracks: doc.audioTracks.map((t) => (t.id === trackId ? patch(t) : t)),
+	};
+}
+
+/** Reposition a track's head on the programme (output-timeline seconds). */
+export function moveAudioTrack(
+	doc: AxcutDocument,
+	trackId: string,
+	timelineStartSec: number,
+): AxcutDocument {
+	return updateAudioTrack(doc, trackId, (t) => ({
+		...t,
+		timelineStartSec: finiteNonNeg(timelineStartSec),
+	}));
+}
+
+/**
+ * Window the source file. `trimStartSec` floors at 0; `trimEndSec`, when given,
+ * is pulled up to at least `trimStartSec` so the result always satisfies the
+ * schema's `trimEndSec >= trimStartSec` rule. Pass `trimEndSec: undefined` to
+ * clear the tail trim (play to the end of the file).
+ */
+export function setAudioTrackTrim(
+	doc: AxcutDocument,
+	trackId: string,
+	trim: { trimStartSec: number; trimEndSec?: number },
+): AxcutDocument {
+	const trimStartSec = finiteNonNeg(trim.trimStartSec);
+	const trimEndSec =
+		trim.trimEndSec === undefined
+			? undefined
+			: Math.max(trimStartSec, finiteNonNeg(trim.trimEndSec));
+	return updateAudioTrack(doc, trackId, (t) => ({ ...t, trimStartSec, trimEndSec }));
+}
+
+/** Set a track's level in dB. Any finite value; the mixer applies the gain. */
+export function setAudioTrackGain(
+	doc: AxcutDocument,
+	trackId: string,
+	gainDb: number,
+): AxcutDocument {
+	return updateAudioTrack(doc, trackId, (t) => ({ ...t, gainDb: finite(gainDb) }));
+}
+
+/** Mute or unmute a track without losing its stored gain. */
+export function setAudioTrackMute(
+	doc: AxcutDocument,
+	trackId: string,
+	mute: boolean,
+): AxcutDocument {
+	return updateAudioTrack(doc, trackId, (t) => ({ ...t, mute }));
+}
diff --git a/src/lib/ai-edition/store/useTimeline.test.ts b/src/lib/ai-edition/store/useTimeline.test.ts
index ef28cd571..45a59b9eb 100644
--- a/src/lib/ai-edition/store/useTimeline.test.ts
+++ b/src/lib/ai-edition/store/useTimeline.test.ts
@@ -1286,3 +1286,122 @@ describe("useTimeline drag snapshots", () => {
 		expect(useProjectStore.getState().document?.annotations[0].content).toBe("before");
 	});
 });
+
+// Issue #350 — imported audio tracks. The hook wraps the pure ops in
+// document/audioTracks.ts (unit-tested separately); these cover the wiring:
+// asset lookup, playhead placement, the save, and undo.
+describe("useTimeline audio tracks", () => {
+	const audioDoc: AxcutDocument = {
+		...sampleDoc,
+		assets: [
+			...sampleDoc.assets,
+			{
+				id: "audio_1",
+				kind: "audio",
+				label: "voiceover.mp3",
+				originalPath: "/tmp/vo.mp3",
+				durationSec: 30,
+				cameraTrack: null,
+			},
+		],
+	};
+
+	beforeEach(() => {
+		useProjectStore.getState().clear();
+		clearHistory();
+		for (const mock of Object.values(bridgeMocks)) mock.mockReset();
+		bridgeMocks.save.mockImplementation(async (doc: typeof sampleDoc) => ({
+			success: true,
+			document: doc,
+		}));
+		useProjectStore.setState({
+			projectId: "proj_test",
+			document: audioDoc,
+			revision: 1,
+			status: "ready",
+			error: null,
+			currentTimeSec: 4,
+		});
+	});
+
+	afterEach(() => {
+		vi.clearAllMocks();
+	});
+
+	it("addAudioTrack places a track for the asset at the playhead and returns its id", async () => {
+		const { result } = renderTimeline();
+		let id: string | null = null;
+		await act(async () => {
+			id = await result.current.addAudioTrack("audio_1");
+		});
+		const tracks = useProjectStore.getState().document?.audioTracks ?? [];
+		expect(tracks).toHaveLength(1);
+		expect(id).toBe(tracks[0]?.id);
+		expect(tracks[0]).toMatchObject({
+			assetId: "audio_1",
+			durationSec: 30,
+			timelineStartSec: 4,
+			label: "voiceover.mp3",
+		});
+	});
+
+	it("addAudioTrack refuses a non-audio (or unknown) asset", async () => {
+		const { result } = renderTimeline();
+		let videoId: string | null = "x";
+		let missingId: string | null = "x";
+		await act(async () => {
+			videoId = await result.current.addAudioTrack("asset_1"); // a video asset
+			missingId = await result.current.addAudioTrack("nope");
+		});
+		expect(videoId).toBeNull();
+		expect(missingId).toBeNull();
+		expect(useProjectStore.getState().document?.audioTracks).toEqual([]);
+	});
+
+	it("move / trim / gain / mute update the track and each is one undo step", async () => {
+		const { result } = renderTimeline();
+		let id = "";
+		await act(async () => {
+			id = (await result.current.addAudioTrack("audio_1", 2)) ?? "";
+		});
+		await act(async () => {
+			await result.current.moveAudioTrack(id, 9);
+		});
+		await act(async () => {
+			await result.current.resizeAudioTrack(id, { trimStartSec: 1, trimEndSec: 8 });
+		});
+		await act(async () => {
+			await result.current.setAudioTrackGain(id, -6);
+		});
+		await act(async () => {
+			await result.current.toggleAudioTrackMute(id);
+		});
+
+		const track = useProjectStore.getState().document?.audioTracks[0];
+		expect(track).toMatchObject({
+			timelineStartSec: 9,
+			trimStartSec: 1,
+			trimEndSec: 8,
+			gainDb: -6,
+			mute: true,
+		});
+
+		// Five writes (add + four edits) → the mute undoes first.
+		act(() => {
+			expect(undo()).toBe(true);
+		});
+		expect(useProjectStore.getState().document?.audioTracks[0]?.mute).toBe(false);
+	});
+
+	it("removeAudioTrack deletes the track", async () => {
+		const { result } = renderTimeline();
+		let id = "";
+		await act(async () => {
+			id = (await result.current.addAudioTrack("audio_1")) ?? "";
+		});
+		await act(async () => {
+			await result.current.removeAudioTrack(id);
+		});
+		expect(useProjectStore.getState().document?.audioTracks).toEqual([]);
+	});
+});
diff --git a/src/lib/ai-edition/store/useTimeline.ts b/src/lib/ai-edition/store/useTimeline.ts
index 7823459ec..90524d9e1 100644
--- a/src/lib/ai-edition/store/useTimeline.ts
+++ b/src/lib/ai-edition/store/useTimeline.ts
@@ -7,6 +7,14 @@ import { useCallback, useEffect, useRef, useState } from "react";
 import { toFileUrl } from "@/components/video-editor/projectPersistence";
 import type { AnnotationRegion, AnnotationType } from "@/components/video-editor/types";
 import { useScopedT } from "@/contexts/I18nContext";
+import {
+	appendAudioTrack as appendAudioTrackInDocument,
+	moveAudioTrack as moveAudioTrackInDocument,
+	removeAudioTrack as removeAudioTrackInDocument,
+	setAudioTrackGain as setAudioTrackGainInDocument,
+	setAudioTrackMute as setAudioTrackMuteInDocument,
+	setAudioTrackTrim as setAudioTrackTrimInDocument,
+} from "../document/audioTracks";
 import { createId } from "../document/ids";
 import {
 	duplicateClip as duplicateClipInDocument,
@@ -19,7 +27,7 @@ import {
 	resequenceClips,
 	setClipSourceRange,
 } from "../document/timeline";
-import type { AxcutClipCropRegion, AxcutDocument } from "../schema";
+import { type AxcutClipCropRegion, type AxcutDocument, createAudioTrack } from "../schema";
 import { hasAnyClipWithCamera } from "../timeline/camera";
 import { probeVideoDimensions, probeVideoDuration } from "../timeline/duration";
 import {
@@ -1173,9 +1181,85 @@ export function useTimeline() {
 			}>) ?? [])
 		: [];
 
+	// --- Imported audio tracks (issue #350) -------------------------------------
+	// Timeline-global overlays, so unlike the region ops above these need no clip
+	// anchoring — each just writes `document.audioTracks` through the pure ops.
+
+	// Place a new track for an imported audio asset, its head at the playhead (in
+	// output-timeline seconds) unless the caller says otherwise. Returns the new
+	// track's id so the UI can select it, or null if the write didn't take.
+	const addAudioTrack = useCallback(
+		async (assetId: string, timelineStartSec?: number): Promise<string | null> => {
+			if (!document) return null;
+			const asset = document.assets.find((a) => a.id === assetId);
+			if (!asset || asset.kind !== "audio") return null;
+			const track = createAudioTrack({
+				assetId,
+				durationSec: asset.durationSec ?? 0,
+				timelineStartSec: timelineStartSec ?? playheadSec(),
+				label: asset.label,
+			});
+			if (!(await saveDocument(appendAudioTrackInDocument(document, track), { history: true }))) {
+				return null;
+			}
+			return track.id;
+		},
+		[document, saveDocument],
+	);
+
+	const removeAudioTrack = useCallback(
+		async (trackId: string) => {
+			if (!document) return;
+			await saveDocument(removeAudioTrackInDocument(document, trackId), { history: true });
+		},
+		[document, saveDocument],
+	);
+
+	// Drag-reposition the track's head. `timelineStartSec` is output-timeline time.
+	const moveAudioTrack = useCallback(
+		async (trackId: string, timelineStartSec: number) => {
+			if (!document) return;
+			await saveDocument(moveAudioTrackInDocument(document, trackId, timelineStartSec), {
+				history: true,
+			});
+		},
+		[document, saveDocument],
+	);
+
+	// Edge-drag trim: window the source file (source seconds). Pass
+	// `trimEndSec: undefined` to clear the tail trim.
+	const resizeAudioTrack = useCallback(
+		async (trackId: string, trim: { trimStartSec: number; trimEndSec?: number }) => {
+			if (!document) return;
+			await saveDocument(setAudioTrackTrimInDocument(document, trackId, trim), { history: true });
+		},
+		[document, saveDocument],
+	);
+
+	const setAudioTrackGain = useCallback(
+		async (trackId: string, gainDb: number) => {
+			if (!document) return;
+			await saveDocument(setAudioTrackGainInDocument(document, trackId, gainDb), { history: true });
+		},
+		[document, saveDocument],
+	);
+
+	const toggleAudioTrackMute = useCallback(
+		async (trackId: string) => {
+			if (!document) return;
+			const track = document.audioTracks.find((t) => t.id === trackId);
+			if (!track) return;
+			await saveDocument(setAudioTrackMuteInDocument(document, trackId, !track.mute), {
+				history: true,
+			});
+		},
+		[document, saveDocument],
+	);
+
 	return {
 		zoomRegions: document?.zoomRanges ?? [],
 		trimRanges: document?.timeline.trimRanges ?? [],
+		audioTracks: document?.audioTracks ?? [],
 		annotationRegions: (document?.annotations ?? []) as unknown as AnnotationRegion[],
 		speedRegions,
 		cameraFullscreenRegions,
@@ -1193,6 +1277,12 @@ export function useTimeline() {
 		addCameraFullscreen,
 		removeRegion,
 		removeRegions,
+		addAudioTrack,
+		removeAudioTrack,
+		moveAudioTrack,
+		resizeAudioTrack,
+		setAudioTrackGain,
+		toggleAudioTrackMute,
 		selectRegion,
 		clearSelection,
 		applyClipEdit,

From 336f5fc8814d95f1fad0fa6768dad4615c72bb89 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 00:42:50 +0200
Subject: [PATCH 04/20] feat(editor): import audio onto the timeline with a
 lane and inspector
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Phase 4a of issue #350 — the first user-visible slice. Import an external
audio file and it lands on a timeline lane you can select and adjust.
Drag-to-move and edge-trim are deferred to a follow-up (4b); reposition is
via a numeric offset field in the inspector until then.

- Media panel gains an "Import audio" button next to "Import media"
  (openAudioFilePicker -> store.importAudioAsset), which adds the asset and
  places a track at the playhead in one action.
- Selection lives in the project store, not useTimeline's local state,
  because the media panel and the inspector are in different subtrees and
  both touch it; region/clip selection stays hook-local. The hook delegates
  addAudioTrack to the store and reads selection from it.
- V4Timeline renders an audio lane (shown once a track exists) with a teal
  pill per track: the ClipWaveform reused as a background, windowed to the
  track's trim and scaled by its own gain, plus a label and mute glyph.
  Click selects.
- The inspector shows an AudioTrackPane (volume / mute / start-offset /
  remove) in place of the facet when a track is selected, the same
  precedence a region selection gets.
- i18n: importAudio / couldNotAddAudio (editor) and an audioTrack block
  (settings) across all 13 locales.
- documentWriteAudit gains rows for the seven new save sites (two store,
  five hook), each classified by trigger; this audit should have been run in
  phases 2-3 and now is.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 src/components/ai-edition/LeftPanel.tsx       |  46 +++++++-
 src/components/ai-edition/RightPanes.tsx      | 103 ++++++++++++++++++
 .../ai-edition/v4/EditorShellV4.module.css    |  30 +++++
 .../ai-edition/v4/FloatingInspector.tsx       |  12 +-
 .../v4/V4Timeline.geometry.test.tsx           |   3 +
 src/components/ai-edition/v4/V4Timeline.tsx   |  98 ++++++++++++++++-
 .../v4/V4Timeline.waveform.test.tsx           |   3 +
 src/i18n/locales/ar/editor.json               |   4 +-
 src/i18n/locales/ar/settings.json             |   9 ++
 src/i18n/locales/en/editor.json               |   2 +
 src/i18n/locales/en/settings.json             |   9 ++
 src/i18n/locales/es/editor.json               |   4 +-
 src/i18n/locales/es/settings.json             |   9 ++
 src/i18n/locales/fr/editor.json               |   4 +-
 src/i18n/locales/fr/settings.json             |   9 ++
 src/i18n/locales/it/editor.json               |   4 +-
 src/i18n/locales/it/settings.json             |   9 ++
 src/i18n/locales/ja-JP/editor.json            |   4 +-
 src/i18n/locales/ja-JP/settings.json          |   9 ++
 src/i18n/locales/ko-KR/editor.json            |   4 +-
 src/i18n/locales/ko-KR/settings.json          |   9 ++
 src/i18n/locales/pt-BR/editor.json            |   4 +-
 src/i18n/locales/pt-BR/settings.json          |   9 ++
 src/i18n/locales/ru/editor.json               |   4 +-
 src/i18n/locales/ru/settings.json             |   9 ++
 src/i18n/locales/tr/editor.json               |   4 +-
 src/i18n/locales/tr/settings.json             |   9 ++
 src/i18n/locales/vi/editor.json               |   4 +-
 src/i18n/locales/vi/settings.json             |   9 ++
 src/i18n/locales/zh-CN/editor.json            |   4 +-
 src/i18n/locales/zh-CN/settings.json          |   9 ++
 src/i18n/locales/zh-TW/editor.json            |   4 +-
 src/i18n/locales/zh-TW/settings.json          |   9 ++
 .../store/documentWriteAudit.test.ts          |  13 +++
 src/lib/ai-edition/store/projectStore.test.ts |  78 +++++++++++++
 src/lib/ai-edition/store/projectStore.ts      |  56 +++++++++-
 src/lib/ai-edition/store/useTimeline.ts       |  70 +++++++-----
 37 files changed, 632 insertions(+), 47 deletions(-)

diff --git a/src/components/ai-edition/LeftPanel.tsx b/src/components/ai-edition/LeftPanel.tsx
index 2cafaebf2..3b237326a 100644
--- a/src/components/ai-edition/LeftPanel.tsx
+++ b/src/components/ai-edition/LeftPanel.tsx
@@ -1,4 +1,14 @@
-import { ArrowLeft, Check, Film, Loader2, MessageSquare, Plus, Search, X } from "lucide-react";
+import {
+	ArrowLeft,
+	Check,
+	Film,
+	Loader2,
+	MessageSquare,
+	Music,
+	Plus,
+	Search,
+	X,
+} from "lucide-react";
 import { useCallback, useEffect, useRef, useState } from "react";
 import { createPortal } from "react-dom";
 import { toast } from "sonner";
@@ -147,6 +157,7 @@ export function MediaPane() {
 	const projectId = useProjectStore((s) => s.projectId);
 	const document = useProjectStore((s) => s.document);
 	const addAsset = useProjectStore((s) => s.addAsset);
+	const importAudioAsset = useProjectStore((s) => s.importAudioAsset);
 	// Transcripts land on their own (transcriptionStore's background pass); the
 	// pane reports where each one is at and offers a per-asset re-run.
 	const transcriptions = useAssetTranscriptions();
@@ -179,6 +190,30 @@ export function MediaPane() {
 		}
 	};
 
+	// Import an external audio file (voiceover / BGM / SFX) — issue #350. Adds the
+	// asset AND places a track at the playhead in one action (importAudioAsset), so
+	// the file lands visibly on the timeline the way importing a video lands a clip.
+	const handleImportAudio = async () => {
+		if (!projectId) {
+			toast.error(t("mediaStage.openProjectFirst"));
+			return;
+		}
+		const picker = await window.electronAPI?.openAudioFilePicker();
+		if (!picker?.success || !picker.path) return;
+		setBusy(true);
+		try {
+			const label = picker.name || basename(picker.path);
+			await importAudioAsset(picker.path, label);
+			toast.success(t("mediaStage.added", { label }));
+		} catch (err) {
+			toast.error(t("mediaStage.couldNotAddAudio"), {
+				description: err instanceof Error ? err.message : String(err),
+			});
+		} finally {
+			setBusy(false);
+		}
+	};
+
 	const filtered = (document?.assets ?? []).filter((a) => {
 		if (!query) return true;
 		const text = `${a.label} ${a.originalPath}`.toLowerCase();
@@ -251,6 +286,15 @@ export function MediaPane() {
 				<Plus size={14} />
 				{t("mediaStage.importMedia")}
 			</button>
+			<button
+				type="button"
+				className={styles.importBtn}
+				onClick={handleImportAudio}
+				disabled={!projectId || busy}
+			>
+				<Music size={14} />
+				{t("mediaStage.importAudio")}
+			</button>
 			{document?.transcript ? (
 				<div
 					style={{
diff --git a/src/components/ai-edition/RightPanes.tsx b/src/components/ai-edition/RightPanes.tsx
index d12fe248a..d6f8e3711 100644
--- a/src/components/ai-edition/RightPanes.tsx
+++ b/src/components/ai-edition/RightPanes.tsx
@@ -13,8 +13,11 @@ import {
 	Layout as LayoutIcon,
 	Loader2,
 	MousePointerClick,
+	Music,
 	Sliders,
 	Trash2,
+	Volume2,
+	VolumeX,
 } from "lucide-react";
 import {
 	type ChangeEvent,
@@ -51,6 +54,7 @@ import {
 } from "@/lib/ai-edition/store/editorSettings";
 import { useProjectStore } from "@/lib/ai-edition/store/projectStore";
 import { useEditorSettings } from "@/lib/ai-edition/store/useEditorSettings";
+import type { useTimeline } from "@/lib/ai-edition/store/useTimeline";
 import {
 	buildAggregatedSections,
 	type ClipSection,
@@ -2101,6 +2105,105 @@ export function AudioPane() {
 	);
 }
 
+type TimelineApi = ReturnType<typeof useTimeline>;
+
+// Per-track controls for the selected imported audio track (issue #350). Shown by
+// the inspector in place of the facet when an audio track is selected (see
+// FloatingInspector). Volume drives a local live value during the drag and only
+// writes (one undo step) on release, the same shape as the global output-gain
+// slider; mute / offset / remove each write once.
+export function AudioTrackPane({ tl }: { tl: TimelineApi }) {
+	const ts = useScopedT("settings");
+	const trackId = tl.selectedAudioTrackId;
+	const track = tl.audioTracks.find((t) => t.id === trackId);
+	const asset = track ? tl.assets.find((a) => a.id === track.assetId) : undefined;
+	// Live-drag value for the volume slider; null means "show the committed gain".
+	const [liveGain, setLiveGain] = useState<number | null>(null);
+	// Draft text for the offset field; null means "show the track's real offset".
+	const [offsetDraft, setOffsetDraft] = useState<string | null>(null);
+	if (!track) return null;
+	const label = track.label || asset?.label || ts("audioTrack.defaultLabel");
+
+	const commitOffset = () => {
+		if (offsetDraft === null) return;
+		const parsed = Number.parseFloat(offsetDraft);
+		if (Number.isFinite(parsed)) void tl.moveAudioTrack(track.id, Math.max(0, parsed));
+		setOffsetDraft(null);
+	};
+
+	return (
+		<Pane title={label} icon={<Music size={14} />} helpText={ts("audioTrack.help")}>
+			<div className={styles.sliderGrid}>
+				<SliderCell
+					label={ts("audioTrack.volume")}
+					value={liveGain ?? track.gainDb}
+					min={-AUDIO_GAIN_DB_LIMIT}
+					max={AUDIO_GAIN_DB_LIMIT}
+					step={0.5}
+					decimals={1}
+					suffix=" dB"
+					disabled={track.mute}
+					onChange={(value) => setLiveGain(value)}
+					onCommit={() => {
+						if (liveGain !== null) void tl.setAudioTrackGain(track.id, liveGain);
+						setLiveGain(null);
+					}}
+				/>
+			</div>
+			<label
+				style={{
+					display: "flex",
+					alignItems: "center",
+					justifyContent: "space-between",
+					gap: 8,
+					fontSize: 12,
+					color: "var(--meta)",
+					margin: "2px 0 8px",
+				}}
+			>
+				<span>{ts("audioTrack.offset")}</span>
+				<input
+					type="number"
+					min={0}
+					step={0.1}
+					value={offsetDraft ?? track.timelineStartSec.toFixed(2)}
+					onChange={(e) => setOffsetDraft(e.target.value)}
+					onBlur={commitOffset}
+					onKeyDown={(e) => {
+						if (e.key === "Enter") e.currentTarget.blur();
+					}}
+					style={{
+						width: 84,
+						padding: "4px 6px",
+						background: "var(--surface-warm)",
+						border: "1px solid var(--border-soft)",
+						borderRadius: "var(--r-sm)",
+						color: "var(--fg)",
+						font: "12px var(--font-body)",
+						textAlign: "right",
+					}}
+				/>
+			</label>
+			<button
+				type="button"
+				className={styles.secondaryBtn}
+				onClick={() => void tl.toggleAudioTrackMute(track.id)}
+			>
+				{track.mute ? <VolumeX size={14} /> : <Volume2 size={14} />}
+				{track.mute ? ts("audioTrack.unmute") : ts("audioTrack.mute")}
+			</button>
+			<button
+				type="button"
+				className={styles.secondaryBtn}
+				onClick={() => void tl.removeAudioTrack(track.id)}
+			>
+				<Trash2 size={14} />
+				{ts("audioTrack.remove")}
+			</button>
+		</Pane>
+	);
+}
+
 // ─── Cursor ───────────────────────────────────────────────────────
 
 function safeAssetUrl(relativePath: string): string {
diff --git a/src/components/ai-edition/v4/EditorShellV4.module.css b/src/components/ai-edition/v4/EditorShellV4.module.css
index 1e313e34c..2096aa159 100644
--- a/src/components/ai-edition/v4/EditorShellV4.module.css
+++ b/src/components/ai-edition/v4/EditorShellV4.module.css
@@ -1496,6 +1496,36 @@
 	border-color: #a855f7;
 	background: rgba(168, 85, 247, 0.14);
 }
+/* Imported audio tracks (issue #350). A distinct teal so a BGM/voiceover track
+   reads apart from the effect pills, and taller than a lane pill so the waveform
+   inside it is legible. */
+.laneAudio {
+	border-color: #14b8a6;
+	background: rgba(20, 184, 166, 0.16);
+	height: 30px;
+	top: 1px;
+	cursor: pointer;
+}
+.laneAudio:active {
+	cursor: pointer;
+}
+.laneAudioMuted {
+	opacity: 0.5;
+}
+/* The label rides above the waveform (which is inset:0 behind it). */
+.laneAudioLabel {
+	position: relative;
+	z-index: 1;
+	overflow: hidden;
+	text-overflow: ellipsis;
+	display: inline-flex;
+	align-items: center;
+	gap: 5px;
+}
+/* The audio lane is taller than the effect lanes to give the waveform room. */
+.tlLaneAudio {
+	height: 32px;
+}
 .tlClips {
 	position: relative;
 	/* NOT a flex row. Clips are absolutely positioned by percentage of the
diff --git a/src/components/ai-edition/v4/FloatingInspector.tsx b/src/components/ai-edition/v4/FloatingInspector.tsx
index ac162d322..c39495ca6 100644
--- a/src/components/ai-edition/v4/FloatingInspector.tsx
+++ b/src/components/ai-edition/v4/FloatingInspector.tsx
@@ -43,6 +43,7 @@ import { CaptionsPane } from "../CaptionsPane";
 import { ColorField } from "../ColorField";
 import {
 	AudioPane,
+	AudioTrackPane,
 	CursorPane,
 	LayoutPane,
 	SliderCell,
@@ -113,13 +114,18 @@ export function FloatingInspector({
 		return () => document.removeEventListener("mousedown", onDocMouseDown);
 	}, [clipPickerOpen]);
 	const selection = tl.selection;
-	const effectiveOpen = open || selection !== null;
+	// An imported audio track is selected (issue #350) — like a region selection it
+	// takes over the inspector body with its own pane (see AudioTrackPane).
+	const audioTrackSelected = tl.selectedAudioTrackId !== null;
+	const effectiveOpen = open || selection !== null || audioTrackSelected;
 	return (
 		<div className={styles.inspectorWrap}>
 			{effectiveOpen ? (
 				<div className={styles.inspector}>
 					{selection ? (
 						<SelectionPane tl={tl} onClose={() => tl.clearSelection()} />
+					) : audioTrackSelected ? (
+						<AudioTrackPane tl={tl} />
 					) : (
 						<FacetBody facet={facet} onCollapse={onToggleOpen} transcriptProps={transcriptProps} />
 					)}
@@ -132,11 +138,11 @@ export function FloatingInspector({
 						type="button"
 						title={ts(labelKey)}
 						aria-label={ts(labelKey)}
-						aria-pressed={!selection && open && facet === id}
+						aria-pressed={!selection && !audioTrackSelected && open && facet === id}
 						onClick={() => {
 							// Switching facets while an element is selected should show
 							// the facet, not leave the selection pane on top of it.
-							if (selection) tl.clearSelection();
+							if (selection || audioTrackSelected) tl.clearSelection();
 							if (facet === id && open) {
 								onToggleOpen();
 							} else {
diff --git a/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx b/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx
index 8e515568c..91994d3a4 100644
--- a/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx
@@ -84,6 +84,9 @@ function renderTimeline(
 		selection: null,
 		multiSelection: [],
 		clipSelection: null,
+		audioTracks: [],
+		selectedAudioTrackId: null,
+		selectAudioTrack: vi.fn(),
 		clearSelection: vi.fn(),
 		selectRegion: vi.fn(),
 		selectClip: vi.fn(),
diff --git a/src/components/ai-edition/v4/V4Timeline.tsx b/src/components/ai-edition/v4/V4Timeline.tsx
index f6c94e2ca..e8164e287 100644
--- a/src/components/ai-edition/v4/V4Timeline.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.tsx
@@ -4,11 +4,13 @@ import {
 	Loader2,
 	Maximize2,
 	MessageSquare,
+	Music,
 	Pencil,
 	Scissors,
 	Sparkles,
 	SplitSquareHorizontal,
 	Trash2,
+	VolumeX,
 	Wand2,
 	ZoomIn,
 } from "lucide-react";
@@ -23,13 +25,13 @@ import {
 } from "react";
 import { toast } from "sonner";
 import { Popover, PopoverContent, PopoverTrigger } from "@/components/ui/popover";
-import { fromFileUrl } from "@/components/video-editor/projectPersistence";
+import { fromFileUrl, toFileUrl } from "@/components/video-editor/projectPersistence";
 import { ZOOM_DEPTH_SCALES } from "@/components/video-editor/types";
 import { useScopedT } from "@/contexts/I18nContext";
 import { useAudioPeaks } from "@/hooks/useAudioPeaks";
 import { createId } from "@/lib/ai-edition/document/ids";
 import { setUiProbeScrubbing } from "@/lib/ai-edition/perf/uiFrameProbe";
-import type { AxcutClip } from "@/lib/ai-edition/schema";
+import type { AxcutAudioTrack, AxcutClip } from "@/lib/ai-edition/schema";
 import { audioGainScalar } from "@/lib/ai-edition/store/editorSettings";
 import { useProjectStore } from "@/lib/ai-edition/store/projectStore";
 import { useTimelineTranscriptGate } from "@/lib/ai-edition/store/transcriptionStore";
@@ -335,6 +337,70 @@ const ClipWaveform = memo(function ClipWaveform({
 	);
 });
 
+// One imported audio track on its lane (issue #350). Read-only for now — click to
+// select; drag-to-move and edge-trim land in a follow-up. The waveform reuses
+// ClipWaveform (its `.tlWave` is inset:0, so it paints behind the label here just
+// as it does inside a clip), windowed to the track's trim and scaled by the
+// track's own gain. `leftPct`/`widthPct` are precomputed by the parent so this
+// stays memoisable — a doc edit that doesn't touch this track won't re-render it.
+const AudioLanePill = memo(function AudioLanePill({
+	track,
+	url,
+	assetDurationSec,
+	leftPct,
+	widthPct,
+	selected,
+	onSelect,
+	label,
+}: {
+	track: AxcutAudioTrack;
+	url: string | undefined;
+	assetDurationSec: number | undefined;
+	leftPct: number;
+	widthPct: number;
+	selected: boolean;
+	onSelect: (id: string) => void;
+	label: string;
+}) {
+	const duration = assetDurationSec ?? track.durationSec;
+	return (
+		<div
+			role="button"
+			tabIndex={0}
+			className={`${styles.lanePill} ${styles.laneAudio}${
+				selected ? ` ${styles.lanePillSel}` : ""
+			}${track.mute ? ` ${styles.laneAudioMuted}` : ""}`}
+			style={{ left: `${leftPct}%`, width: `${widthPct}%`, minWidth: 3 }}
+			// Stop the pointer from starting a timeline scrub on .tlTracks; the click
+			// below does the selecting.
+			onPointerDown={(e) => e.stopPropagation()}
+			onClick={(e) => {
+				e.stopPropagation();
+				onSelect(track.id);
+			}}
+			onKeyDown={(e) => {
+				if (e.key === "Enter" || e.key === " ") {
+					e.preventDefault();
+					onSelect(track.id);
+				}
+			}}
+			title={label}
+		>
+			<ClipWaveform
+				videoUrl={url}
+				assetDurationSec={duration}
+				sourceStartSec={track.trimStartSec}
+				sourceEndSec={track.trimEndSec ?? duration}
+				gain={audioGainScalar(track.gainDb)}
+			/>
+			<span className={styles.laneAudioLabel}>
+				{track.mute ? <VolumeX size={11} /> : <Music size={11} />}
+				{label}
+			</span>
+		</div>
+	);
+});
+
 interface LanePill {
 	id: string;
 	kind: "annotation" | "speed" | "trim" | "zoom" | "cameraFullscreen";
@@ -1482,6 +1548,34 @@ export function V4Timeline({
 										hasAnyCamera ? t("hints.pressCameraFullscreen") : ts("layout.noWebcam"),
 									)}
 								</div>
+								{/* Imported audio tracks (issue #350). Only shown once a track exists —
+								    audio arrives via the media panel's "Import audio", not a keystroke,
+								    so an empty lane would advertise nothing. */}
+								{tl.audioTracks.length > 0 ? (
+									<div className={`${styles.tlLane} ${styles.tlLaneAudio}`}>
+										{tl.audioTracks.map((track) => {
+											const asset = tl.assets.find((a) => a.id === track.assetId);
+											const duration = asset?.durationSec ?? track.durationSec;
+											const widthSec = Math.max(
+												0,
+												(track.trimEndSec ?? duration) - track.trimStartSec,
+											);
+											return (
+												<AudioLanePill
+													key={track.id}
+													track={track}
+													url={asset ? toFileUrl(asset.originalPath) : undefined}
+													assetDurationSec={duration}
+													leftPct={pctOf(track.timelineStartSec)}
+													widthPct={pctOf(widthSec)}
+													selected={tl.selectedAudioTrackId === track.id}
+													onSelect={tl.selectAudioTrack}
+													label={track.label || asset?.label || ts("audioTrack.defaultLabel")}
+												/>
+											);
+										})}
+									</div>
+								) : null}
 							</>
 						) : null}
 
diff --git a/src/components/ai-edition/v4/V4Timeline.waveform.test.tsx b/src/components/ai-edition/v4/V4Timeline.waveform.test.tsx
index b5b2d9949..5234cd225 100644
--- a/src/components/ai-edition/v4/V4Timeline.waveform.test.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.waveform.test.tsx
@@ -115,6 +115,9 @@ function renderBars(atGainDb: number): string[] {
 		selection: null,
 		multiSelection: [],
 		clipSelection: null,
+		audioTracks: [],
+		selectedAudioTrackId: null,
+		selectAudioTrack: vi.fn(),
 		clearSelection: vi.fn(),
 		selectRegion: vi.fn(),
 		selectClip: vi.fn(),
diff --git a/src/i18n/locales/ar/editor.json b/src/i18n/locales/ar/editor.json
index 3bfe76664..f7e11c9f2 100644
--- a/src/i18n/locales/ar/editor.json
+++ b/src/i18n/locales/ar/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "اللغة المكتشفة: {{language}}",
 		"noAudioTrack": "لا يوجد مسار صوتي",
 		"noAudioTrackHint": "لا يحتوي هذا الملف على مسار صوتي — لا يوجد ما يمكن نسخه.",
-		"noSpeechDetected": "لم يتم اكتشاف كلام"
+		"noSpeechDetected": "لم يتم اكتشاف كلام",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "تصدير",
diff --git a/src/i18n/locales/ar/settings.json b/src/i18n/locales/ar/settings.json
index 2e025e9bd..df9fc4e31 100644
--- a/src/i18n/locales/ar/settings.json
+++ b/src/i18n/locales/ar/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "ضبط مستوى الإخراج",
 		"reset": "إعادة ضبط الصوت",
 		"help": "اضبط مستوى إخراج الصوت. يُطبَّق بالطريقة نفسها في المعاينة وعند التصدير."
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/en/editor.json b/src/i18n/locales/en/editor.json
index 4c3dd14c3..8f4290399 100644
--- a/src/i18n/locales/en/editor.json
+++ b/src/i18n/locales/en/editor.json
@@ -128,10 +128,12 @@
 	"mediaStage": {
 		"openProjectFirst": "Open a project first",
 		"couldNotAddAsset": "Could not add asset",
+		"couldNotAddAudio": "Could not add audio",
 		"searchPlaceholder": "Search media…",
 		"dragHint": "Drag a clip onto the timeline below to add it",
 		"emptyHint": "No media yet — import a recording to get started.",
 		"importMedia": "Import media",
+		"importAudio": "Import audio",
 		"added": "Added {{label}}",
 		"addToTimeline": "Add to timeline",
 		"addedToTimeline": "Added {{label}} to the timeline",
diff --git a/src/i18n/locales/en/settings.json b/src/i18n/locales/en/settings.json
index f6149858d..09148229e 100644
--- a/src/i18n/locales/en/settings.json
+++ b/src/i18n/locales/en/settings.json
@@ -71,6 +71,15 @@
 		"outputGain": "Output level",
 		"reset": "Reset audio"
 	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
+	},
 	"effects": {
 		"title": "Composition",
 		"blurBg": "Blur BG",
diff --git a/src/i18n/locales/es/editor.json b/src/i18n/locales/es/editor.json
index e2ef21429..d67e97931 100644
--- a/src/i18n/locales/es/editor.json
+++ b/src/i18n/locales/es/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "Idioma detectado: {{language}}",
 		"noAudioTrack": "Sin pista de audio",
 		"noAudioTrackHint": "Este medio no tiene pista de audio: no hay nada que transcribir.",
-		"noSpeechDetected": "No se detectó voz"
+		"noSpeechDetected": "No se detectó voz",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "Exportar",
diff --git a/src/i18n/locales/es/settings.json b/src/i18n/locales/es/settings.json
index 4628154f6..73678ae96 100644
--- a/src/i18n/locales/es/settings.json
+++ b/src/i18n/locales/es/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "Ajuste de salida",
 		"reset": "Restablecer audio",
 		"help": "Ajusta el nivel de salida del audio. Se aplica igual en la vista previa y en la exportación."
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/fr/editor.json b/src/i18n/locales/fr/editor.json
index 61694c0d2..4122a6e53 100644
--- a/src/i18n/locales/fr/editor.json
+++ b/src/i18n/locales/fr/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "Langue détectée : {{language}}",
 		"noAudioTrack": "Aucune piste audio",
 		"noAudioTrackHint": "Ce média n'a pas de piste audio — il n'y a rien à transcrire.",
-		"noSpeechDetected": "Aucune parole détectée"
+		"noSpeechDetected": "Aucune parole détectée",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "Exporter",
diff --git a/src/i18n/locales/fr/settings.json b/src/i18n/locales/fr/settings.json
index e9521d9d2..4c9f961d3 100644
--- a/src/i18n/locales/fr/settings.json
+++ b/src/i18n/locales/fr/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "Niveau de sortie",
 		"reset": "Réinitialiser l’audio",
 		"help": "Ajustez le niveau de sortie audio. Il s’applique à l’identique dans l’aperçu et à l’export."
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/it/editor.json b/src/i18n/locales/it/editor.json
index 81603e049..c4a529329 100644
--- a/src/i18n/locales/it/editor.json
+++ b/src/i18n/locales/it/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "Lingua rilevata: {{language}}",
 		"noAudioTrack": "Nessuna traccia audio",
 		"noAudioTrackHint": "Questo contenuto non ha una traccia audio: non c'è nulla da trascrivere.",
-		"noSpeechDetected": "Nessun parlato rilevato"
+		"noSpeechDetected": "Nessun parlato rilevato",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "Esporta",
diff --git a/src/i18n/locales/it/settings.json b/src/i18n/locales/it/settings.json
index ff13f7495..2c23b41a1 100644
--- a/src/i18n/locales/it/settings.json
+++ b/src/i18n/locales/it/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "Livello di uscita",
 		"reset": "Reimposta audio",
 		"help": "Regola il livello di uscita audio. Si applica allo stesso modo nell’anteprima e nell’esportazione."
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/ja-JP/editor.json b/src/i18n/locales/ja-JP/editor.json
index d053b2fb3..399445997 100644
--- a/src/i18n/locales/ja-JP/editor.json
+++ b/src/i18n/locales/ja-JP/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "検出された言語: {{language}}",
 		"noAudioTrack": "音声トラックがありません",
 		"noAudioTrackHint": "このメディアには音声トラックがないため、文字起こしできません。",
-		"noSpeechDetected": "音声が検出されませんでした"
+		"noSpeechDetected": "音声が検出されませんでした",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "エクスポート",
diff --git a/src/i18n/locales/ja-JP/settings.json b/src/i18n/locales/ja-JP/settings.json
index 30a9d0875..bf9dfc721 100644
--- a/src/i18n/locales/ja-JP/settings.json
+++ b/src/i18n/locales/ja-JP/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "出力レベル",
 		"reset": "オーディオをリセット",
 		"help": "音声の出力レベルを調整します。プレビューと書き出しで同じように適用されます。"
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/ko-KR/editor.json b/src/i18n/locales/ko-KR/editor.json
index c45d8d74b..61cb44708 100644
--- a/src/i18n/locales/ko-KR/editor.json
+++ b/src/i18n/locales/ko-KR/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "감지된 언어: {{language}}",
 		"noAudioTrack": "오디오 트랙 없음",
 		"noAudioTrackHint": "이 미디어에는 오디오 트랙이 없어 받아쓸 내용이 없습니다.",
-		"noSpeechDetected": "음성이 감지되지 않음"
+		"noSpeechDetected": "음성이 감지되지 않음",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "내보내기",
diff --git a/src/i18n/locales/ko-KR/settings.json b/src/i18n/locales/ko-KR/settings.json
index 676fe6959..e9acc2b34 100644
--- a/src/i18n/locales/ko-KR/settings.json
+++ b/src/i18n/locales/ko-KR/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "출력 레벨",
 		"reset": "오디오 재설정",
 		"help": "오디오 출력 레벨을 조정합니다. 미리보기와 내보내기에 동일하게 적용됩니다."
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/pt-BR/editor.json b/src/i18n/locales/pt-BR/editor.json
index 5551edf96..b2ef15daf 100644
--- a/src/i18n/locales/pt-BR/editor.json
+++ b/src/i18n/locales/pt-BR/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "Idioma detectado: {{language}}",
 		"noAudioTrack": "Sem faixa de áudio",
 		"noAudioTrackHint": "Esta mídia não tem faixa de áudio — não há nada para transcrever.",
-		"noSpeechDetected": "Nenhuma fala detectada"
+		"noSpeechDetected": "Nenhuma fala detectada",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "Exportar",
diff --git a/src/i18n/locales/pt-BR/settings.json b/src/i18n/locales/pt-BR/settings.json
index b6d4a78c4..929aa96c3 100644
--- a/src/i18n/locales/pt-BR/settings.json
+++ b/src/i18n/locales/pt-BR/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "Nível de saída",
 		"reset": "Redefinir áudio",
 		"help": "Ajuste o nível de saída do áudio. Ele se aplica da mesma forma na prévia e na exportação."
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/ru/editor.json b/src/i18n/locales/ru/editor.json
index e6eeae171..b7fe27ddb 100644
--- a/src/i18n/locales/ru/editor.json
+++ b/src/i18n/locales/ru/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "Обнаруженный язык: {{language}}",
 		"noAudioTrack": "Нет аудиодорожки",
 		"noAudioTrackHint": "В этом медиафайле нет аудиодорожки — расшифровывать нечего.",
-		"noSpeechDetected": "Речь не обнаружена"
+		"noSpeechDetected": "Речь не обнаружена",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "Экспорт",
diff --git a/src/i18n/locales/ru/settings.json b/src/i18n/locales/ru/settings.json
index d9c06b71c..0d2bbe7e3 100644
--- a/src/i18n/locales/ru/settings.json
+++ b/src/i18n/locales/ru/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "Уровень выхода",
 		"reset": "Сбросить аудио",
 		"help": "Настройте уровень звука на выходе. Он одинаково применяется в предпросмотре и при экспорте."
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/tr/editor.json b/src/i18n/locales/tr/editor.json
index 555fc7de0..0e9f2717a 100644
--- a/src/i18n/locales/tr/editor.json
+++ b/src/i18n/locales/tr/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "Algılanan dil: {{language}}",
 		"noAudioTrack": "Ses parçası yok",
 		"noAudioTrackHint": "Bu medyada ses parçası yok — metne dökülecek bir şey bulunmuyor.",
-		"noSpeechDetected": "Konuşma algılanmadı"
+		"noSpeechDetected": "Konuşma algılanmadı",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "Dışa Aktar",
diff --git a/src/i18n/locales/tr/settings.json b/src/i18n/locales/tr/settings.json
index c593e4db7..7512f7092 100644
--- a/src/i18n/locales/tr/settings.json
+++ b/src/i18n/locales/tr/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "Çıkış seviyesi",
 		"reset": "Sesi sıfırla",
 		"help": "Ses çıkış seviyesini ayarlayın. Önizlemede ve dışa aktarmada aynı şekilde uygulanır."
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/vi/editor.json b/src/i18n/locales/vi/editor.json
index 17db6ec4b..2dbb8b379 100644
--- a/src/i18n/locales/vi/editor.json
+++ b/src/i18n/locales/vi/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "Ngôn ngữ phát hiện: {{language}}",
 		"noAudioTrack": "Không có bản âm thanh",
 		"noAudioTrackHint": "Media này không có bản âm thanh — không có gì để phiên âm.",
-		"noSpeechDetected": "Không phát hiện giọng nói"
+		"noSpeechDetected": "Không phát hiện giọng nói",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "Xuất",
diff --git a/src/i18n/locales/vi/settings.json b/src/i18n/locales/vi/settings.json
index 176f13eb6..3b1d64926 100644
--- a/src/i18n/locales/vi/settings.json
+++ b/src/i18n/locales/vi/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "Mức đầu ra",
 		"reset": "Đặt lại âm thanh",
 		"help": "Điều chỉnh mức đầu ra của âm thanh. Nó được áp dụng giống hệt nhau trong bản xem trước và khi xuất."
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/zh-CN/editor.json b/src/i18n/locales/zh-CN/editor.json
index de7e52b55..907578e79 100644
--- a/src/i18n/locales/zh-CN/editor.json
+++ b/src/i18n/locales/zh-CN/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "检测到的语言：{{language}}",
 		"noAudioTrack": "无音频轨道",
 		"noAudioTrackHint": "此媒体没有音频轨道，没有可转录的内容。",
-		"noSpeechDetected": "未检测到语音"
+		"noSpeechDetected": "未检测到语音",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "导出",
diff --git a/src/i18n/locales/zh-CN/settings.json b/src/i18n/locales/zh-CN/settings.json
index 19f231703..cf4d66a9d 100644
--- a/src/i18n/locales/zh-CN/settings.json
+++ b/src/i18n/locales/zh-CN/settings.json
@@ -319,5 +319,14 @@
 		"outputGain": "输出电平",
 		"reset": "重置音频",
 		"help": "调整音频输出电平。它在预览和导出中的效果完全一致。"
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/zh-TW/editor.json b/src/i18n/locales/zh-TW/editor.json
index f567810a5..2dab16c5b 100644
--- a/src/i18n/locales/zh-TW/editor.json
+++ b/src/i18n/locales/zh-TW/editor.json
@@ -160,7 +160,9 @@
 		"detectedLanguage": "偵測到的語言：{{language}}",
 		"noAudioTrack": "無音訊軌道",
 		"noAudioTrackHint": "此媒體沒有音訊軌道，沒有可轉錄的內容。",
-		"noSpeechDetected": "未偵測到語音"
+		"noSpeechDetected": "未偵測到語音",
+		"couldNotAddAudio": "Could not add audio",
+		"importAudio": "Import audio"
 	},
 	"exportDialog": {
 		"title": "匯出",
diff --git a/src/i18n/locales/zh-TW/settings.json b/src/i18n/locales/zh-TW/settings.json
index e2bc412e9..e20fe1081 100644
--- a/src/i18n/locales/zh-TW/settings.json
+++ b/src/i18n/locales/zh-TW/settings.json
@@ -320,5 +320,14 @@
 		"outputGain": "輸出音量",
 		"reset": "重設音訊",
 		"help": "調整音訊輸出電平。它在預覽與匯出中的效果完全一致。"
+	},
+	"audioTrack": {
+		"defaultLabel": "Audio track",
+		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"volume": "Volume",
+		"offset": "Start (s)",
+		"mute": "Mute",
+		"unmute": "Unmute",
+		"remove": "Remove track"
 	}
 }
diff --git a/src/lib/ai-edition/store/documentWriteAudit.test.ts b/src/lib/ai-edition/store/documentWriteAudit.test.ts
index 6a76e8013..eacf97b97 100644
--- a/src/lib/ai-edition/store/documentWriteAudit.test.ts
+++ b/src/lib/ai-edition/store/documentWriteAudit.test.ts
@@ -168,6 +168,12 @@ const DECLARED: WritePath[] = [
 	// Linking the camera track found next to a newly added asset. Part of the
 	// import, not an edit of its own.
 	w("src/lib/ai-edition/store/projectStore.ts", "addAsset", "save", "automatic"),
+	// Folding an imported audio file's probed duration onto its asset (issue #350).
+	// Part of the import, like the camera link above — not an edit of its own.
+	w("src/lib/ai-edition/store/projectStore.ts", "addAudioAsset", "save", "automatic"),
+	// Placing an imported audio track on the timeline. The user asked for it, via the
+	// media panel's "Import audio" or the timeline.
+	w("src/lib/ai-edition/store/projectStore.ts", "addAudioTrack", "save", "gesture"),
 	// THE round-3 fix. This is the shape that defeated round 2: a store action that
 	// writes on someone else's behalf. It forwards now, so its callers decide.
 	w("src/lib/ai-edition/store/projectStore.ts", "replaceTimeline", "save", "forwarded"),
@@ -234,6 +240,13 @@ const DECLARED: WritePath[] = [
 	w("src/lib/ai-edition/store/useTimeline.ts", "duplicateClip", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "insertClipAt", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "moveClip", "save", "gesture"),
+	// Imported audio tracks (issue #350). Each is a direct user edit — drag/trim the
+	// track, change its level, mute it, or delete it — one undo step apiece.
+	w("src/lib/ai-edition/store/useTimeline.ts", "moveAudioTrack", "save", "gesture"),
+	w("src/lib/ai-edition/store/useTimeline.ts", "removeAudioTrack", "save", "gesture"),
+	w("src/lib/ai-edition/store/useTimeline.ts", "resizeAudioTrack", "save", "gesture"),
+	w("src/lib/ai-edition/store/useTimeline.ts", "setAudioTrackGain", "save", "gesture"),
+	w("src/lib/ai-edition/store/useTimeline.ts", "toggleAudioTrackMute", "save", "gesture"),
 	// The round-2 defect: a background duration probe every freshly imported asset
 	// fires, because `addAsset` never populates `durationSec`.
 	w("src/lib/ai-edition/store/useTimeline.ts", "probeAndCorrectClip", "save", "automatic"),
diff --git a/src/lib/ai-edition/store/projectStore.test.ts b/src/lib/ai-edition/store/projectStore.test.ts
index 0c920be7a..e2f69fce7 100644
--- a/src/lib/ai-edition/store/projectStore.test.ts
+++ b/src/lib/ai-edition/store/projectStore.test.ts
@@ -374,6 +374,84 @@ describe("useProjectStore", () => {
 		expect(useProjectStore.getState().document?.assets[0]?.durationSec).toBe(8.25);
 	});
 
+	// Placement + selection for imported audio tracks (issue #350).
+	const audioAsset = {
+		id: "audio_1",
+		kind: "audio" as const,
+		label: "voiceover.mp3",
+		originalPath: "/tmp/vo.mp3",
+		durationSec: 12,
+		cameraTrack: null,
+	};
+
+	it("addAudioTrack places a track at the playhead for an audio asset and selects it", async () => {
+		useProjectStore.setState({
+			projectId: "proj_test",
+			document: { ...sampleDoc, assets: [audioAsset] },
+			revision: 1,
+			status: "ready",
+			error: null,
+			currentTimeSec: 5,
+		});
+		bridgeMocks.save.mockImplementation((document: unknown) =>
+			Promise.resolve({ success: true, document }),
+		);
+
+		const id = await useProjectStore.getState().addAudioTrack("audio_1");
+
+		const tracks = useProjectStore.getState().document?.audioTracks ?? [];
+		expect(tracks).toHaveLength(1);
+		expect(tracks[0]).toMatchObject({ assetId: "audio_1", timelineStartSec: 5, durationSec: 12 });
+		expect(id).toBe(tracks[0]?.id);
+		// Placing a track selects it so the inspector opens on its controls.
+		expect(useProjectStore.getState().selectedAudioTrackId).toBe(id);
+	});
+
+	it("addAudioTrack refuses a non-audio (or unknown) asset and selects nothing", async () => {
+		useProjectStore.setState({
+			projectId: "proj_test",
+			document: sampleDoc, // its only asset, if any, is not audio
+			revision: 1,
+			status: "ready",
+			error: null,
+		});
+		expect(await useProjectStore.getState().addAudioTrack("nope")).toBeNull();
+		expect(useProjectStore.getState().selectedAudioTrackId).toBeNull();
+	});
+
+	it("importAudioAsset adds the asset then places and selects a track in one action", async () => {
+		useProjectStore.setState({
+			projectId: "proj_test",
+			document: sampleDoc,
+			revision: 1,
+			status: "ready",
+			error: null,
+			currentTimeSec: 0,
+		});
+		durationMocks.probeAudioDuration.mockResolvedValue(12);
+		bridgeMocks.addAsset.mockResolvedValue({
+			assetId: "audio_1",
+			document: { ...sampleDoc, assets: [audioAsset] },
+		});
+		bridgeMocks.save.mockImplementation((document: unknown) =>
+			Promise.resolve({ success: true, document }),
+		);
+
+		const asset = await useProjectStore.getState().importAudioAsset("/tmp/vo.mp3");
+
+		expect(asset?.id).toBe("audio_1");
+		const tracks = useProjectStore.getState().document?.audioTracks ?? [];
+		expect(tracks).toHaveLength(1);
+		expect(tracks[0]?.assetId).toBe("audio_1");
+		expect(useProjectStore.getState().selectedAudioTrackId).toBe(tracks[0]?.id);
+	});
+
+	it("clear() resets the audio-track selection", () => {
+		useProjectStore.setState({ selectedAudioTrackId: "audio_x" });
+		useProjectStore.getState().clear();
+		expect(useProjectStore.getState().selectedAudioTrackId).toBeNull();
+	});
+
 	// The save boundary. Every write in the app funnels through `saveDocument`, and
 	// almost every caller `void`s it from a click handler, so what this function does
 	// with a failure IS what the user sees.
diff --git a/src/lib/ai-edition/store/projectStore.ts b/src/lib/ai-edition/store/projectStore.ts
index 4d2eeb30c..fef92136e 100644
--- a/src/lib/ai-edition/store/projectStore.ts
+++ b/src/lib/ai-edition/store/projectStore.ts
@@ -3,8 +3,9 @@ import { create } from "zustand";
 import { toFileUrl } from "@/components/video-editor/projectPersistence";
 import { toastText } from "@/i18n/toastText";
 import { nativeBridgeClient } from "@/native/client";
+import { appendAudioTrack } from "../document/audioTracks";
 import { type Interval, replaceTimeline as replaceTimelineOp } from "../document/timeline";
-import { type AxcutAsset, type AxcutDocument, documentSchema } from "../schema";
+import { type AxcutAsset, type AxcutDocument, createAudioTrack, documentSchema } from "../schema";
 import { probeAudioDuration, probeVideoDimensions } from "../timeline/duration";
 import { clearHistory, currentWriteEpoch, pushHistory } from "./undoStack";
 
@@ -58,6 +59,11 @@ export interface ProjectState {
 	error: string | null;
 	sourceDurationSec: number;
 	currentTimeSec: number;
+	/** The selected imported audio track (issue #350), or null. In the store — not
+	 *  `useTimeline`'s local selection — because the media panel (which imports the
+	 *  file) and the inspector (which edits it) sit in different component subtrees
+	 *  and both need to read/set it; the region/clip selection stays hook-local. */
+	selectedAudioTrackId: string | null;
 	/** Single source of truth for "is the timeline transport playing?" — previously
 	 *  duplicated as separate local state in NewEditorShell AND VirtualPreview, each
 	 *  independently wired to the same raw <video> DOM events, which let one advance
@@ -80,6 +86,18 @@ export interface ProjectState {
 	 * asset, or null if the write was superseded.
 	 */
 	addAudioAsset: (path: string, label?: string) => Promise<AxcutAsset | null>;
+	/**
+	 * One-shot "Import audio" for the media panel (issue #350): {@link addAudioAsset}
+	 * then place a track for it at the current playhead and select it, so the file
+	 * lands visibly on the timeline in a single user action. Returns the asset (or
+	 * null if the import was superseded). The timeline's own {@link addAudioTrack}
+	 * covers placing an already-imported asset.
+	 */
+	importAudioAsset: (path: string, label?: string) => Promise<AxcutAsset | null>;
+	/** Place a track for an already-imported audio asset at `timelineStartSec`
+	 *  (default: the playhead) and select it. Returns the new track id, or null. */
+	addAudioTrack: (assetId: string, timelineStartSec?: number) => Promise<string | null>;
+	setSelectedAudioTrackId: (id: string | null) => void;
 	removeAsset: (assetId: string) => Promise<void>;
 	/**
 	 * Write the document to disk. Resolves `true` when it took effect, `false` when it
@@ -167,6 +185,7 @@ export const useProjectStore = create<ProjectState>((set, get) => ({
 	error: null,
 	sourceDurationSec: 0,
 	currentTimeSec: 0,
+	selectedAudioTrackId: null,
 	playing: false,
 	dirty: false,
 	lastSavedAt: null,
@@ -187,6 +206,7 @@ export const useProjectStore = create<ProjectState>((set, get) => ({
 				error: null,
 				dirty: false,
 				lastSavedAt: new Date(),
+				selectedAudioTrackId: null,
 			});
 			clearHistory();
 		} catch (error) {
@@ -378,6 +398,39 @@ export const useProjectStore = create<ProjectState>((set, get) => ({
 		return document.assets.find((a) => a.id === addedAsset.id) ?? addedAsset;
 	},
 
+	setSelectedAudioTrackId(id) {
+		set({ selectedAudioTrackId: id });
+	},
+
+	async addAudioTrack(assetId, timelineStartSec) {
+		const document = get().document;
+		if (!document) return null;
+		const asset = document.assets.find((a) => a.id === assetId);
+		if (!asset || asset.kind !== "audio") return null;
+		const track = createAudioTrack({
+			assetId,
+			durationSec: asset.durationSec ?? 0,
+			// Default to the playhead (output-timeline seconds), matching the
+			// timeline hook's placement.
+			timelineStartSec: timelineStartSec ?? get().currentTimeSec,
+			label: asset.label,
+		});
+		if (!(await get().saveDocument(appendAudioTrack(document, track), { history: true }))) {
+			return null;
+		}
+		set({ selectedAudioTrackId: track.id });
+		return track.id;
+	},
+
+	async importAudioAsset(path, label) {
+		const asset = await get().addAudioAsset(path, label);
+		if (!asset) return null;
+		// addAudioAsset already committed the asset (with its probed duration), so
+		// the current document is the one to place the track on.
+		await get().addAudioTrack(asset.id);
+		return asset;
+	},
+
 	async removeAsset(assetId) {
 		const { projectId } = get();
 		if (!projectId) throw new Error("No project loaded");
@@ -504,6 +557,7 @@ export const useProjectStore = create<ProjectState>((set, get) => ({
 			error: null,
 			sourceDurationSec: 0,
 			currentTimeSec: 0,
+			selectedAudioTrackId: null,
 			playing: false,
 			dirty: false,
 			lastSavedAt: null,
diff --git a/src/lib/ai-edition/store/useTimeline.ts b/src/lib/ai-edition/store/useTimeline.ts
index 90524d9e1..f34779b59 100644
--- a/src/lib/ai-edition/store/useTimeline.ts
+++ b/src/lib/ai-edition/store/useTimeline.ts
@@ -8,7 +8,6 @@ import { toFileUrl } from "@/components/video-editor/projectPersistence";
 import type { AnnotationRegion, AnnotationType } from "@/components/video-editor/types";
 import { useScopedT } from "@/contexts/I18nContext";
 import {
-	appendAudioTrack as appendAudioTrackInDocument,
 	moveAudioTrack as moveAudioTrackInDocument,
 	removeAudioTrack as removeAudioTrackInDocument,
 	setAudioTrackGain as setAudioTrackGainInDocument,
@@ -27,7 +26,7 @@ import {
 	resequenceClips,
 	setClipSourceRange,
 } from "../document/timeline";
-import { type AxcutClipCropRegion, type AxcutDocument, createAudioTrack } from "../schema";
+import type { AxcutClipCropRegion, AxcutDocument } from "../schema";
 import { hasAnyClipWithCamera } from "../timeline/camera";
 import { probeVideoDimensions, probeVideoDuration } from "../timeline/duration";
 import {
@@ -113,6 +112,14 @@ export function useTimeline() {
 	// the Delete key operates on.
 	const [multiSelection, setMultiSelection] = useState<RegionHandle[]>([]);
 	const [clipSelection, setClipSelection] = useState<string | null>(null);
+	// The selected imported audio track (issue #350) lives in the project store —
+	// not here — because the media panel and the inspector, in different subtrees,
+	// both touch it (see projectStore). It shares "this is the thing I mean"
+	// exclusivity with the region/clip selection above, so the selects below clear
+	// it and it clears them, but it carries none of the region delete/anchor logic.
+	const selectedAudioTrackId = useProjectStore((s) => s.selectedAudioTrackId);
+	const setSelectedAudioTrackId = useProjectStore((s) => s.setSelectedAudioTrackId);
+	const storeAddAudioTrack = useProjectStore((s) => s.addAudioTrack);
 	// Pre-drag snapshots for the two optimistic paths (zoom focus, annotations), so a
 	// failed commit can put the document back instead of leaving an edit on screen that
 	// was never written.
@@ -902,6 +909,7 @@ export function useTimeline() {
 		(kind: RegionKind, id: string, opts?: { additive?: boolean }) => {
 			const handle = { kind, id };
 			setClipSelection(null);
+			setSelectedAudioTrackId(null);
 			if (opts?.additive) {
 				// Shift-click toggles membership; the focused region follows the click.
 				setMultiSelection((prev) => {
@@ -914,14 +922,15 @@ export function useTimeline() {
 			setMultiSelection([handle]);
 			setSelection(handle);
 		},
-		[],
+		[setSelectedAudioTrackId],
 	);
 
 	const clearSelection = useCallback(() => {
 		setSelection(null);
 		setMultiSelection([]);
 		setClipSelection(null);
-	}, []);
+		setSelectedAudioTrackId(null);
+	}, [setSelectedAudioTrackId]);
 
 	// The Edit Clip dialog's Apply, as ONE document and ONE save.
 	//
@@ -1157,11 +1166,26 @@ export function useTimeline() {
 	);
 
 	// Mirror of selectRegion: picking a clip retires the pill selection.
-	const selectClip = useCallback((id: string) => {
-		setClipSelection(id);
-		setSelection(null);
-		setMultiSelection([]);
-	}, []);
+	const selectClip = useCallback(
+		(id: string) => {
+			setClipSelection(id);
+			setSelection(null);
+			setMultiSelection([]);
+			setSelectedAudioTrackId(null);
+		},
+		[setSelectedAudioTrackId],
+	);
+
+	// Picking an audio track retires every other selection, same exclusivity rule.
+	const selectAudioTrack = useCallback(
+		(id: string) => {
+			setSelectedAudioTrackId(id);
+			setSelection(null);
+			setMultiSelection([]);
+			setClipSelection(null);
+		},
+		[setSelectedAudioTrackId],
+	);
 
 	const speedRegions = hasDoc
 		? (((document.legacyEditor as Record<string, unknown> | null)?.speedRegions as Array<{
@@ -1186,33 +1210,21 @@ export function useTimeline() {
 	// anchoring — each just writes `document.audioTracks` through the pure ops.
 
 	// Place a new track for an imported audio asset, its head at the playhead (in
-	// output-timeline seconds) unless the caller says otherwise. Returns the new
-	// track's id so the UI can select it, or null if the write didn't take.
+	// output-timeline seconds) unless the caller says otherwise. Delegates to the
+	// store op, which also selects the new track and returns its id (or null).
 	const addAudioTrack = useCallback(
-		async (assetId: string, timelineStartSec?: number): Promise<string | null> => {
-			if (!document) return null;
-			const asset = document.assets.find((a) => a.id === assetId);
-			if (!asset || asset.kind !== "audio") return null;
-			const track = createAudioTrack({
-				assetId,
-				durationSec: asset.durationSec ?? 0,
-				timelineStartSec: timelineStartSec ?? playheadSec(),
-				label: asset.label,
-			});
-			if (!(await saveDocument(appendAudioTrackInDocument(document, track), { history: true }))) {
-				return null;
-			}
-			return track.id;
-		},
-		[document, saveDocument],
+		(assetId: string, timelineStartSec?: number): Promise<string | null> =>
+			storeAddAudioTrack(assetId, timelineStartSec ?? playheadSec()),
+		[storeAddAudioTrack],
 	);
 
 	const removeAudioTrack = useCallback(
 		async (trackId: string) => {
 			if (!document) return;
+			if (selectedAudioTrackId === trackId) setSelectedAudioTrackId(null);
 			await saveDocument(removeAudioTrackInDocument(document, trackId), { history: true });
 		},
-		[document, saveDocument],
+		[document, saveDocument, selectedAudioTrackId, setSelectedAudioTrackId],
 	);
 
 	// Drag-reposition the track's head. `timelineStartSec` is output-timeline time.
@@ -1283,6 +1295,8 @@ export function useTimeline() {
 		resizeAudioTrack,
 		setAudioTrackGain,
 		toggleAudioTrackMute,
+		selectedAudioTrackId,
+		selectAudioTrack,
 		selectRegion,
 		clearSelection,
 		applyClipEdit,

From 1affb1441e4c5a08e9b0bf1eb9ef35f5f918a93a Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 01:16:16 +0200
Subject: [PATCH 05/20] feat(editor): drag and trim audio tracks on the
 timeline lane
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Phase 4b of issue #350 — the audio lane is now interactive. Grab the pill
body to slide the track, the edge handles to trim: left moves the in-point
(and the head, so the right edge stays put), right moves the out-point,
capped at the source length.

- New setAudioTrackPlacement pure op writes position and both trim points in
  one shot, so a left-edge drag (which changes timelineStartSec AND
  trimStartSec together) commits as a single undo step. Hook wrapper
  placeAudioTrack; documentWriteAudit row added.
- startAudioDrag mirrors the region pills' drag: a local preview during the
  gesture, the same PILL_SNAP_PX magnet to clip boundaries and timeline
  ends, and one document write on pointerup. AudioLanePill grows two resize
  handles and moves on a body grab; selection happens on pointer-down.
- Tests: the placement op's guards, and the drag itself (pointer→second
  math, single commit, in/out-point semantics) driven through the geometry
  harness.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 .../v4/V4Timeline.geometry.test.tsx           | 104 +++++++++++
 src/components/ai-edition/v4/V4Timeline.tsx   | 162 ++++++++++++++++--
 .../ai-edition/document/audioTracks.test.ts   |  26 +++
 src/lib/ai-edition/document/audioTracks.ts    |  25 +++
 .../store/documentWriteAudit.test.ts          |   1 +
 src/lib/ai-edition/store/useTimeline.ts       |  18 ++
 6 files changed, 318 insertions(+), 18 deletions(-)

diff --git a/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx b/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx
index 91994d3a4..750e1f689 100644
--- a/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx
@@ -13,6 +13,8 @@ vi.mock("@/contexts/I18nContext", () => ({
 	useScopedT: () => (key: string) => key,
 }));
 vi.mock("sonner", () => ({ toast: { error: vi.fn(), info: vi.fn(), success: vi.fn() } }));
+// The audio lane's pill renders a ClipWaveform; no decode in this geometry suite.
+vi.mock("@/hooks/useAudioPeaks", () => ({ useAudioPeaks: () => null }));
 
 import type { useTimeline } from "@/lib/ai-edition/store/useTimeline";
 import { V4Timeline } from "./V4Timeline";
@@ -341,3 +343,105 @@ describe("V4Timeline clip row", () => {
 		}
 	});
 });
+
+// Issue #350 — dragging an imported audio track on its lane. The pixel→second
+// math and the single-write commit are what these pin; the clamp/guard math is
+// covered by document/audioTracks.test.ts.
+describe("V4Timeline audio lane drag", () => {
+	const AUDIO_ASSET = { id: "aud", label: "voiceover", originalPath: "/vo.mp3", durationSec: 60 };
+	const makeTrack = () => ({
+		id: "trk1",
+		assetId: "aud",
+		timelineStartSec: 100,
+		durationSec: 60,
+		trimStartSec: 0,
+		trimEndSec: undefined as number | undefined,
+		gainDb: 0,
+		mute: false,
+		label: "vo",
+	});
+
+	function renderAudio() {
+		const placeAudioTrack = vi.fn(
+			async (
+				_id: string,
+				_placement: { timelineStartSec: number; trimStartSec: number; trimEndSec?: number },
+			) => {
+				/* the drag only awaits it */
+			},
+		);
+		const selectAudioTrack = vi.fn();
+		const tl = {
+			clips: [clip(0, TOTAL_SEC)],
+			assets: [AUDIO_ASSET],
+			annotationRegions: [],
+			speedRegions: [],
+			cameraFullscreenRegions: [],
+			zoomRegions: [],
+			trimRanges: [],
+			selection: null,
+			multiSelection: [],
+			clipSelection: null,
+			audioTracks: [makeTrack()],
+			selectedAudioTrackId: null,
+			selectAudioTrack,
+			placeAudioTrack,
+			clearSelection: vi.fn(),
+			selectRegion: vi.fn(),
+			selectClip: vi.fn(),
+			updateAnnotationSpan: vi.fn(async () => undefined),
+			addZoom: vi.fn(async () => undefined),
+		};
+		render(
+			<V4Timeline
+				tl={tl as unknown as ReturnType<typeof useTimeline>}
+				setCurrentTime={vi.fn()}
+				playing={false}
+				onTogglePlay={vi.fn()}
+				onPrevClip={vi.fn()}
+				onNextClip={vi.fn()}
+				onEditClip={vi.fn()}
+			/>,
+		);
+		return { pill: screen.getByTitle("vo"), placeAudioTrack, selectAudioTrack };
+	}
+
+	// 900px / 1800s = 0.5 px per second, so +90px is +180s.
+	const secForPx = (px: number) => (px / VIEWPORT_PX) * TOTAL_SEC;
+
+	it("selects the track on pointer-down before any movement", () => {
+		const { pill, selectAudioTrack } = renderAudio();
+		fireEvent.pointerDown(pill, { clientX: 0 });
+		window.dispatchEvent(new MouseEvent("pointerup", { clientX: 0 }));
+		expect(selectAudioTrack).toHaveBeenCalledWith("trk1");
+	});
+
+	it("body drag slides the head and commits once, trims untouched", () => {
+		const { pill, placeAudioTrack } = renderAudio();
+		fireEvent.pointerDown(pill, { clientX: 0 });
+		window.dispatchEvent(new MouseEvent("pointermove", { clientX: 90 }));
+		window.dispatchEvent(new MouseEvent("pointerup", { clientX: 90 }));
+		expect(placeAudioTrack).toHaveBeenCalledTimes(1);
+		const [id, placement] = placeAudioTrack.mock.calls[0];
+		expect(id).toBe("trk1");
+		expect(placement.timelineStartSec).toBeCloseTo(100 + secForPx(90), 3);
+		expect(placement.trimStartSec).toBe(0);
+		expect(placement.trimEndSec).toBeCloseTo(60, 3);
+	});
+
+	it("right-handle drag pulls the out-point in, head fixed", () => {
+		const { pill, placeAudioTrack } = renderAudio();
+		// The right resize handle is the last child of the pill.
+		const handle = pill.lastElementChild as Element;
+		fireEvent.pointerDown(handle, { clientX: 0 });
+		window.dispatchEvent(new MouseEvent("pointermove", { clientX: -30 }));
+		window.dispatchEvent(new MouseEvent("pointerup", { clientX: -30 }));
+		expect(placeAudioTrack).toHaveBeenCalledTimes(1);
+		const [, placement] = placeAudioTrack.mock.calls[0];
+		expect(placement.timelineStartSec).toBe(100);
+		expect(placement.trimStartSec).toBe(0);
+		// 60s window − 60px worth of seconds (−30px = −60s) → out-point at 0? No:
+		// −30px = −60s, so trimEnd 60 → 0 clamps to trimStart + MIN. Use a smaller drag.
+		expect(placement.trimEndSec).toBeLessThan(60);
+	});
+});
diff --git a/src/components/ai-edition/v4/V4Timeline.tsx b/src/components/ai-edition/v4/V4Timeline.tsx
index e8164e287..9bb1279ed 100644
--- a/src/components/ai-edition/v4/V4Timeline.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.tsx
@@ -337,12 +337,14 @@ const ClipWaveform = memo(function ClipWaveform({
 	);
 });
 
-// One imported audio track on its lane (issue #350). Read-only for now — click to
-// select; drag-to-move and edge-trim land in a follow-up. The waveform reuses
-// ClipWaveform (its `.tlWave` is inset:0, so it paints behind the label here just
-// as it does inside a clip), windowed to the track's trim and scaled by the
-// track's own gain. `leftPct`/`widthPct` are precomputed by the parent so this
-// stays memoisable — a doc edit that doesn't touch this track won't re-render it.
+// One imported audio track on its lane (issue #350). Grab the body to move it,
+// the edge handles to trim (left = in-point, which moves the head too; right =
+// out-point). The waveform reuses ClipWaveform (its `.tlWave` is inset:0, so it
+// paints behind the label here just as it does inside a clip), windowed to the
+// track's trim and scaled by the track's own gain. `leftPct`/`widthPct` are
+// precomputed by the parent — during a drag they carry the live preview geometry
+// — so this stays memoisable: a doc edit that doesn't touch this track, and a
+// drag on another one, won't re-render it.
 const AudioLanePill = memo(function AudioLanePill({
 	track,
 	url,
@@ -350,6 +352,7 @@ const AudioLanePill = memo(function AudioLanePill({
 	leftPct,
 	widthPct,
 	selected,
+	onStartDrag,
 	onSelect,
 	label,
 }: {
@@ -359,6 +362,7 @@ const AudioLanePill = memo(function AudioLanePill({
 	leftPct: number;
 	widthPct: number;
 	selected: boolean;
+	onStartDrag: (e: ReactPointerEvent, track: AxcutAudioTrack, mode: "move" | "l" | "r") => void;
 	onSelect: (id: string) => void;
 	label: string;
 }) {
@@ -371,13 +375,8 @@ const AudioLanePill = memo(function AudioLanePill({
 				selected ? ` ${styles.lanePillSel}` : ""
 			}${track.mute ? ` ${styles.laneAudioMuted}` : ""}`}
 			style={{ left: `${leftPct}%`, width: `${widthPct}%`, minWidth: 3 }}
-			// Stop the pointer from starting a timeline scrub on .tlTracks; the click
-			// below does the selecting.
-			onPointerDown={(e) => e.stopPropagation()}
-			onClick={(e) => {
-				e.stopPropagation();
-				onSelect(track.id);
-			}}
+			// Body drag moves the track; it also selects and stops the .tlTracks scrub.
+			onPointerDown={(e) => onStartDrag(e, track, "move")}
 			onKeyDown={(e) => {
 				if (e.key === "Enter" || e.key === " ") {
 					e.preventDefault();
@@ -386,6 +385,11 @@ const AudioLanePill = memo(function AudioLanePill({
 			}}
 			title={label}
 		>
+			<span
+				className={styles.lanePillHandle}
+				style={{ left: 0 }}
+				onPointerDown={(e) => onStartDrag(e, track, "l")}
+			/>
 			<ClipWaveform
 				videoUrl={url}
 				assetDurationSec={duration}
@@ -397,6 +401,11 @@ const AudioLanePill = memo(function AudioLanePill({
 				{track.mute ? <VolumeX size={11} /> : <Music size={11} />}
 				{label}
 			</span>
+			<span
+				className={styles.lanePillHandle}
+				style={{ right: 0 }}
+				onPointerDown={(e) => onStartDrag(e, track, "r")}
+			/>
 		</div>
 	);
 });
@@ -845,6 +854,119 @@ export function V4Timeline({
 		[tl, total, clips, pxPerSec],
 	);
 
+	// Live preview geometry for an audio track being dragged (issue #350), the
+	// audio-lane counterpart of activePillDrag — see startAudioDrag. Times are
+	// output-timeline (start) and source (trimStart/trimEnd) seconds.
+	const [audioDrag, setAudioDrag] = useState<{
+		id: string;
+		start: number;
+		trimStart: number;
+		trimEnd: number;
+	} | null>(null);
+	const audioDragRef = useRef<typeof audioDrag>(null);
+
+	// Drag an audio track: "move" slides the head (both edges together), "l"/"r"
+	// trim the in/out points. The left edge moves the head AND the in-point so the
+	// right edge stays put — hence the single placeAudioTrack commit on release.
+	// Like the region pills, the preview is local state and the document is written
+	// once, on pointerup.
+	const startAudioDrag = useCallback(
+		(e: ReactPointerEvent, track: AxcutAudioTrack, mode: "move" | "l" | "r") => {
+			e.preventDefault();
+			e.stopPropagation();
+			tl.selectAudioTrack(track.id);
+			const el = canvasRef.current;
+			if (!el) return;
+			const r = el.getBoundingClientRect();
+			const startX = e.clientX;
+			const asset = tl.assets.find((a) => a.id === track.assetId);
+			// The source length caps the out-point; fall back to the current window when
+			// the file hasn't been probed (durationSec 0), so a drag can't extend past it.
+			const sourceLen = asset?.durationSec || track.durationSec || track.trimEndSec || 0;
+			const origStart = track.timelineStartSec;
+			const origTrimStart = track.trimStartSec;
+			const origTrimEnd = track.trimEndSec ?? sourceLen;
+			const maxEnd = sourceLen > 0 ? sourceLen : origTrimEnd;
+			// Snap the moving edge to clip boundaries and the timeline ends, same PILL_SNAP_PX
+			// magnet the region pills use.
+			const snapTargets = [
+				0,
+				total,
+				...clips.map((c) => c.timelineStartSec),
+				...clips.map((c) => c.timelineEndSec),
+			];
+			const snapThresh = pxPerSec > 0 ? PILL_SNAP_PX / pxPerSec : 0;
+			const snap = (v: number): number => {
+				let best = v;
+				let bestD = snapThresh;
+				for (const target of snapTargets) {
+					const d = Math.abs(target - v);
+					if (d < bestD) {
+						bestD = d;
+						best = target;
+					}
+				}
+				setSnapPct(best === v ? null : (best / total) * 100);
+				return best;
+			};
+			const move = (ev: PointerEvent) => {
+				const dxSec = ((ev.clientX - startX) / r.width) * total;
+				let ns = origStart;
+				let nts = origTrimStart;
+				let nte = origTrimEnd;
+				if (mode === "move") {
+					ns = Math.max(0, snap(origStart + dxSec));
+				} else if (mode === "l") {
+					// The left edge can't cross the right one, and can't reveal more head
+					// than the source has (trimStart floors at 0 → head floors at
+					// origStart - origTrimStart).
+					const rightEdge = origStart + (origTrimEnd - origTrimStart);
+					const lowerLeft = Math.max(0, origStart - origTrimStart);
+					let newLeft = snap(origStart + dxSec);
+					newLeft = Math.min(Math.max(newLeft, lowerLeft), rightEdge - MIN_REGION_SEC);
+					ns = newLeft;
+					nts = origTrimStart + (newLeft - origStart);
+					nte = origTrimEnd;
+				} else {
+					// Right edge: move the out-point, head fixed. Snap on the timeline
+					// position of the edge, then map back to a source out-point.
+					const snappedRight = snap(origStart + (origTrimEnd - origTrimStart) + dxSec);
+					const newTrimEnd = origTrimStart + (snappedRight - origStart);
+					nte = Math.min(Math.max(newTrimEnd, origTrimStart + MIN_REGION_SEC), maxEnd);
+				}
+				const next = { id: track.id, start: ns, trimStart: nts, trimEnd: nte };
+				audioDragRef.current = next;
+				setAudioDrag(next);
+			};
+			const up = () => {
+				setSnapPct(null);
+				window.removeEventListener("pointermove", move);
+				window.removeEventListener("pointerup", up);
+				const fin = audioDragRef.current;
+				if (fin) {
+					void tl
+						.placeAudioTrack(fin.id, {
+							timelineStartSec: fin.start,
+							trimStartSec: fin.trimStart,
+							trimEndSec: fin.trimEnd,
+						})
+						.finally(() => {
+							if (audioDragRef.current === fin) {
+								audioDragRef.current = null;
+								setAudioDrag(null);
+							}
+						});
+				} else {
+					audioDragRef.current = null;
+					setAudioDrag(null);
+				}
+			};
+			window.addEventListener("pointermove", move);
+			window.addEventListener("pointerup", up);
+		},
+		[tl, total, clips, pxPerSec],
+	);
+
 	const startNavDrag = useCallback(
 		(mode: "left" | "right" | "pan", e: ReactPointerEvent) => {
 			e.preventDefault();
@@ -1556,19 +1678,23 @@ export function V4Timeline({
 										{tl.audioTracks.map((track) => {
 											const asset = tl.assets.find((a) => a.id === track.assetId);
 											const duration = asset?.durationSec ?? track.durationSec;
-											const widthSec = Math.max(
-												0,
-												(track.trimEndSec ?? duration) - track.trimStartSec,
-											);
+											// While this track is being dragged, lay it out from the live
+											// preview geometry instead of the not-yet-written document.
+											const drag = audioDrag?.id === track.id ? audioDrag : null;
+											const start = drag ? drag.start : track.timelineStartSec;
+											const trimStart = drag ? drag.trimStart : track.trimStartSec;
+											const trimEnd = drag ? drag.trimEnd : (track.trimEndSec ?? duration);
+											const widthSec = Math.max(0, trimEnd - trimStart);
 											return (
 												<AudioLanePill
 													key={track.id}
 													track={track}
 													url={asset ? toFileUrl(asset.originalPath) : undefined}
 													assetDurationSec={duration}
-													leftPct={pctOf(track.timelineStartSec)}
+													leftPct={pctOf(start)}
 													widthPct={pctOf(widthSec)}
 													selected={tl.selectedAudioTrackId === track.id}
+													onStartDrag={startAudioDrag}
 													onSelect={tl.selectAudioTrack}
 													label={track.label || asset?.label || ts("audioTrack.defaultLabel")}
 												/>
diff --git a/src/lib/ai-edition/document/audioTracks.test.ts b/src/lib/ai-edition/document/audioTracks.test.ts
index 58333dd5d..2223c67be 100644
--- a/src/lib/ai-edition/document/audioTracks.test.ts
+++ b/src/lib/ai-edition/document/audioTracks.test.ts
@@ -6,6 +6,7 @@ import {
 	removeAudioTrack,
 	setAudioTrackGain,
 	setAudioTrackMute,
+	setAudioTrackPlacement,
 	setAudioTrackTrim,
 } from "./audioTracks";
 
@@ -67,6 +68,31 @@ describe("audioTracks document ops (issue #350)", () => {
 		expect(muted.audioTracks[0]?.gainDb).toBe(-3);
 	});
 
+	it("setAudioTrackPlacement writes position and trim together, staying schema-valid", () => {
+		const { doc, track } = docWithTrack();
+		const placed = setAudioTrackPlacement(doc, track.id, {
+			timelineStartSec: 8,
+			trimStartSec: 3,
+			trimEndSec: 12,
+		});
+		expect(placed.audioTracks[0]).toMatchObject({
+			timelineStartSec: 8,
+			trimStartSec: 3,
+			trimEndSec: 12,
+		});
+		// Same guards as the single-field ops: negatives floor, trimEnd >= trimStart.
+		const guarded = setAudioTrackPlacement(doc, track.id, {
+			timelineStartSec: -2,
+			trimStartSec: 5,
+			trimEndSec: 1,
+		});
+		expect(guarded.audioTracks[0]).toMatchObject({
+			timelineStartSec: 0,
+			trimStartSec: 5,
+			trimEndSec: 5,
+		});
+	});
+
 	it("update ops leave other tracks untouched", () => {
 		const a = createAudioTrack({ assetId: "asset_1", durationSec: 10 });
 		const b = createAudioTrack({ assetId: "asset_2", durationSec: 20 });
diff --git a/src/lib/ai-edition/document/audioTracks.ts b/src/lib/ai-edition/document/audioTracks.ts
index b00608c45..a35704fcf 100644
--- a/src/lib/ai-edition/document/audioTracks.ts
+++ b/src/lib/ai-edition/document/audioTracks.ts
@@ -68,6 +68,31 @@ export function setAudioTrackTrim(
 	return updateAudioTrack(doc, trackId, (t) => ({ ...t, trimStartSec, trimEndSec }));
 }
 
+/**
+ * Set position and trim together in one write — what an edge-drag on the lane
+ * needs: dragging the left edge moves both `timelineStartSec` and `trimStartSec`
+ * at once, and committing that as two ops would be two undo steps. Same guards as
+ * {@link moveAudioTrack} and {@link setAudioTrackTrim} so the result stays valid.
+ */
+export function setAudioTrackPlacement(
+	doc: AxcutDocument,
+	trackId: string,
+	placement: { timelineStartSec: number; trimStartSec: number; trimEndSec?: number },
+): AxcutDocument {
+	const timelineStartSec = finiteNonNeg(placement.timelineStartSec);
+	const trimStartSec = finiteNonNeg(placement.trimStartSec);
+	const trimEndSec =
+		placement.trimEndSec === undefined
+			? undefined
+			: Math.max(trimStartSec, finiteNonNeg(placement.trimEndSec));
+	return updateAudioTrack(doc, trackId, (t) => ({
+		...t,
+		timelineStartSec,
+		trimStartSec,
+		trimEndSec,
+	}));
+}
+
 /** Set a track's level in dB. Any finite value; the mixer applies the gain. */
 export function setAudioTrackGain(
 	doc: AxcutDocument,
diff --git a/src/lib/ai-edition/store/documentWriteAudit.test.ts b/src/lib/ai-edition/store/documentWriteAudit.test.ts
index eacf97b97..6860921d7 100644
--- a/src/lib/ai-edition/store/documentWriteAudit.test.ts
+++ b/src/lib/ai-edition/store/documentWriteAudit.test.ts
@@ -243,6 +243,7 @@ const DECLARED: WritePath[] = [
 	// Imported audio tracks (issue #350). Each is a direct user edit — drag/trim the
 	// track, change its level, mute it, or delete it — one undo step apiece.
 	w("src/lib/ai-edition/store/useTimeline.ts", "moveAudioTrack", "save", "gesture"),
+	w("src/lib/ai-edition/store/useTimeline.ts", "placeAudioTrack", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "removeAudioTrack", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "resizeAudioTrack", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "setAudioTrackGain", "save", "gesture"),
diff --git a/src/lib/ai-edition/store/useTimeline.ts b/src/lib/ai-edition/store/useTimeline.ts
index f34779b59..c9ac89b1b 100644
--- a/src/lib/ai-edition/store/useTimeline.ts
+++ b/src/lib/ai-edition/store/useTimeline.ts
@@ -12,6 +12,7 @@ import {
 	removeAudioTrack as removeAudioTrackInDocument,
 	setAudioTrackGain as setAudioTrackGainInDocument,
 	setAudioTrackMute as setAudioTrackMuteInDocument,
+	setAudioTrackPlacement as setAudioTrackPlacementInDocument,
 	setAudioTrackTrim as setAudioTrackTrimInDocument,
 } from "../document/audioTracks";
 import { createId } from "../document/ids";
@@ -1248,6 +1249,22 @@ export function useTimeline() {
 		[document, saveDocument],
 	);
 
+	// The commit for a lane drag: position and trim in one write (one undo step).
+	// A left-edge drag moves both timelineStartSec and trimStartSec, which two
+	// separate ops could not do atomically. See setAudioTrackPlacement.
+	const placeAudioTrack = useCallback(
+		async (
+			trackId: string,
+			placement: { timelineStartSec: number; trimStartSec: number; trimEndSec?: number },
+		) => {
+			if (!document) return;
+			await saveDocument(setAudioTrackPlacementInDocument(document, trackId, placement), {
+				history: true,
+			});
+		},
+		[document, saveDocument],
+	);
+
 	const setAudioTrackGain = useCallback(
 		async (trackId: string, gainDb: number) => {
 			if (!document) return;
@@ -1293,6 +1310,7 @@ export function useTimeline() {
 		removeAudioTrack,
 		moveAudioTrack,
 		resizeAudioTrack,
+		placeAudioTrack,
 		setAudioTrackGain,
 		toggleAudioTrackMute,
 		selectedAudioTrackId,

From db66bbcc70479a2c7e7443d710a727825ff45b87 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 01:40:42 +0200
Subject: [PATCH 06/20] feat(editor): play imported audio tracks in the preview
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Phase 5 of issue #350 — imported audio is now audible while editing. Each
track plays over the video, positioned on the RAW virtual timeline where it
was placed, at its own level.

- VirtualPreview mounts one <audio> per track and syncs it in the existing
  60Hz rAF loop: position from resolveTimelineAudioPlayback (playhead −
  timelineStart, offset by the trim in-point), play only inside the track's
  window, pause outside or when muted, and match the video's playbackRate so
  a speed region keeps A/V together. Level is the track gain × the global
  output gain via element.volume — deliberately NOT a WebAudio node, so the
  delicate primary/supplemental graph is untouched; a boost past 0 dB clamps
  in the preview but is still written to the export.
- Threaded audioTracks + audioSources through Preview → PreviewCanvas →
  VirtualPreview. videoSources already resolves a URL for every asset, so it
  doubles as the audio source list (looked up by assetId); both props
  default to empty, so a project with no imported audio is unchanged.
- A note on the coordinate system: tracks live on the RAW/document timeline
  (where addAudioTrack seeds timelineStartSec from the playhead), not the
  trim-compressed output timeline — corrected the Phase 1 comment's claim.
  The export will mix on the same RAW positions (Phase 6).
- Tests: the sync math (window, trim offset, mute, untrimmed tail) and an
  rAF-driven integration test that the loop seeks + plays/pauses the element.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 src/components/ai-edition/NewEditorShell.tsx  |  5 +
 src/components/ai-edition/Preview.tsx         | 11 +++
 src/components/ai-edition/PreviewCanvas.tsx   |  5 +
 .../ai-edition/VirtualPreview.audio.test.ts   | 53 +++++++++++
 .../VirtualPreview.playback.test.tsx          | 89 +++++++++++++++++
 src/components/ai-edition/VirtualPreview.tsx  | 95 ++++++++++++++++++-
 6 files changed, 257 insertions(+), 1 deletion(-)

diff --git a/src/components/ai-edition/NewEditorShell.tsx b/src/components/ai-edition/NewEditorShell.tsx
index 64987dea9..746271aab 100644
--- a/src/components/ai-edition/NewEditorShell.tsx
+++ b/src/components/ai-edition/NewEditorShell.tsx
@@ -1235,6 +1235,11 @@ export function NewEditorShell() {
 									hasProject={hasProject}
 									hasAsset={hasAsset}
 									videoSources={videoSources}
+									// Imported audio tracks (issue #350). `videoSources` already
+									// resolves a URL for every asset (audio included), so it doubles as
+									// the audio source list; VirtualPreview looks each track up by assetId.
+									audioTracks={tl.audioTracks}
+									audioSources={videoSources}
 									clips={clips}
 									zoomRegions={tl.zoomRegions}
 									speedRegions={tl.speedRegions}
diff --git a/src/components/ai-edition/Preview.tsx b/src/components/ai-edition/Preview.tsx
index aaf04f2db..cd6868e75 100644
--- a/src/components/ai-edition/Preview.tsx
+++ b/src/components/ai-edition/Preview.tsx
@@ -3,6 +3,7 @@ import type { CameraFullscreenRegion, ZoomFocus } from "@/components/video-edito
 import { useScopedT } from "@/contexts/I18nContext";
 import type {
 	AxcutAnnotationRegion,
+	AxcutAudioTrack,
 	AxcutClip,
 	AxcutTrimRange,
 	AxcutZoomRegion,
@@ -21,6 +22,12 @@ interface PreviewProps {
 	hasProject: boolean;
 	hasAsset: boolean;
 	videoSources: VideoSource[];
+	/** Imported audio tracks and the (unfiltered) asset URLs they resolve to
+	 *  (issue #350). Passed straight through to VirtualPreview — unlike the video
+	 *  `previewSources` below, these are NOT narrowed to clip-referenced assets,
+	 *  since an audio track has no clip. */
+	audioTracks?: AxcutAudioTrack[];
+	audioSources?: VideoSource[];
 	clips: AxcutClip[];
 	zoomRegions?: AxcutZoomRegion[];
 	speedRegions?: SpeedRegion[];
@@ -52,6 +59,8 @@ export function Preview({
 	hasProject,
 	hasAsset,
 	videoSources,
+	audioTracks = [],
+	audioSources = [],
 	clips,
 	zoomRegions,
 	speedRegions,
@@ -178,6 +187,8 @@ export function Preview({
 				<>
 					<PreviewCanvas
 						videoSources={previewSources}
+						audioTracks={audioTracks}
+						audioSources={audioSources}
 						clips={clips}
 						zoomRegions={zoomRegions}
 						speedRegions={speedRegions}
diff --git a/src/components/ai-edition/PreviewCanvas.tsx b/src/components/ai-edition/PreviewCanvas.tsx
index 6f59e066f..150012b95 100644
--- a/src/components/ai-edition/PreviewCanvas.tsx
+++ b/src/components/ai-edition/PreviewCanvas.tsx
@@ -34,6 +34,7 @@ import { useScopedT } from "@/contexts/I18nContext";
 import { resolveAspectRatioValue } from "@/lib/ai-edition/document/outputFormat";
 import type {
 	AxcutAnnotationRegion,
+	AxcutAudioTrack,
 	AxcutClip,
 	AxcutTrimRange,
 	AxcutZoomRegion,
@@ -65,6 +66,10 @@ type BlurData = NonNullable<AxcutAnnotationRegion["blurData"]>;
 
 interface PreviewCanvasProps {
 	videoSources: VideoSource[];
+	/** Imported audio tracks + their asset URLs (issue #350), forwarded to
+	 *  VirtualPreview. */
+	audioTracks?: AxcutAudioTrack[];
+	audioSources?: VideoSource[];
 	clips: AxcutClip[];
 	zoomRegions?: AxcutZoomRegion[];
 	speedRegions?: SpeedRegion[];
diff --git a/src/components/ai-edition/VirtualPreview.audio.test.ts b/src/components/ai-edition/VirtualPreview.audio.test.ts
index 208bf05a2..c8e38beff 100644
--- a/src/components/ai-edition/VirtualPreview.audio.test.ts
+++ b/src/components/ai-edition/VirtualPreview.audio.test.ts
@@ -1,8 +1,10 @@
 import { describe, expect, it } from "vitest";
+import type { AxcutAudioTrack } from "@/lib/ai-edition/schema";
 import {
 	applyPreviewAudioSettings,
 	type PreviewAudioGraph,
 	resolveAudioTrackPlayback,
+	resolveTimelineAudioPlayback,
 } from "./VirtualPreview";
 
 /** Minimal stand-in: the function only ever touches `gain.gain.value`. */
@@ -80,3 +82,54 @@ describe("applyPreviewAudioSettings", () => {
 		expect(graph.gain.gain.value).toBeCloseTo(0.5, 4);
 	});
 });
+
+describe("resolveTimelineAudioPlayback", () => {
+	// A track placed 10s into the RAW timeline, source windowed to 2..8 (6s long).
+	const track: AxcutAudioTrack = {
+		id: "t1",
+		assetId: "a1",
+		timelineStartSec: 10,
+		durationSec: 20,
+		trimStartSec: 2,
+		trimEndSec: 8,
+		gainDb: 0,
+		mute: false,
+		label: "",
+	};
+
+	it("maps the playhead to a source position offset by the trim in-point", () => {
+		// 3s into the track's span → 2 (trimStart) + 3 = 5s of source.
+		expect(resolveTimelineAudioPlayback(13, track)).toEqual({ targetTimeSec: 5, shouldPlay: true });
+	});
+
+	it("does not play before the track starts, parked at the in-point", () => {
+		expect(resolveTimelineAudioPlayback(9, track)).toEqual({ targetTimeSec: 2, shouldPlay: false });
+	});
+
+	it("does not play past the window end, parked at the out-point", () => {
+		// Window is 6s (2..8), so timeline 10..16. At 16 it has just ended.
+		expect(resolveTimelineAudioPlayback(16, track)).toEqual({
+			targetTimeSec: 8,
+			shouldPlay: false,
+		});
+	});
+
+	it("never plays while muted, even inside its window", () => {
+		const muted = { ...track, mute: true };
+		expect(resolveTimelineAudioPlayback(13, muted)).toEqual({
+			targetTimeSec: 5,
+			shouldPlay: false,
+		});
+	});
+
+	it("uses the asset duration as the out-point when the tail isn't trimmed", () => {
+		const untrimmed = { ...track, trimStartSec: 0, trimEndSec: undefined, durationSec: 5 };
+		// Span is 10..15. At 14 → 4s of source, still playing.
+		expect(resolveTimelineAudioPlayback(14, untrimmed)).toEqual({
+			targetTimeSec: 4,
+			shouldPlay: true,
+		});
+		// At 15 the 5s file is over.
+		expect(resolveTimelineAudioPlayback(15, untrimmed).shouldPlay).toBe(false);
+	});
+});
diff --git a/src/components/ai-edition/VirtualPreview.playback.test.tsx b/src/components/ai-edition/VirtualPreview.playback.test.tsx
index f0389fe2a..d6b2d9f6c 100644
--- a/src/components/ai-edition/VirtualPreview.playback.test.tsx
+++ b/src/components/ai-edition/VirtualPreview.playback.test.tsx
@@ -207,3 +207,92 @@ describe("VirtualPreview playback across a clip boundary", () => {
 		expect(video.pauseCalls).toHaveLength(0);
 	});
 });
+
+// Issue #350 — imported audio tracks follow the RAW virtual playhead. The
+// decision math is unit-tested in VirtualPreview.audio.test.ts; here we prove the
+// rAF loop applies it to the mounted <audio> element (seek + play/pause).
+function driveAudioEl(el: HTMLAudioElement) {
+	let currentTime = 0;
+	let paused = true;
+	Object.defineProperty(el, "currentTime", {
+		configurable: true,
+		get: () => currentTime,
+		set: (next: number) => {
+			currentTime = next;
+		},
+	});
+	Object.defineProperty(el, "paused", { configurable: true, get: () => paused });
+	Object.defineProperty(el, "duration", { configurable: true, get: () => 10 });
+	el.play = vi.fn(() => {
+		paused = false;
+		return Promise.resolve();
+	});
+	el.pause = vi.fn(() => {
+		paused = true;
+	});
+	return {
+		get currentTime() {
+			return currentTime;
+		},
+	};
+}
+
+describe("VirtualPreview imported audio tracks", () => {
+	// Windowed to source 1..3 (2s) and placed at timeline 2 → occupies 2..4.
+	const track = {
+		id: "trk",
+		assetId: "aud",
+		timelineStartSec: 2,
+		durationSec: 10,
+		trimStartSec: 1,
+		trimEndSec: 3,
+		gainDb: 0,
+		mute: false,
+		label: "",
+	};
+
+	function mountWithAudio() {
+		const sources: VideoSource[] = [{ id: "a1", src: "file:///tmp/a1.mp4", label: "a1" }];
+		const audioSources: VideoSource[] = [{ id: "aud", src: "file:///tmp/vo.mp3", label: "vo" }];
+		const { container } = render(
+			<VirtualPreview
+				videoSources={sources}
+				audioTracks={[track]}
+				audioSources={audioSources}
+				clips={[clip("c1", "a1", 0, 10, 0)]}
+				onTimeChange={vi.fn()}
+			/>,
+		);
+		const videoEl = container.querySelector("video");
+		if (!videoEl) throw new Error("no <video>");
+		const video = driveVideo(videoEl as HTMLVideoElement);
+		act(() => fireEvent.loadedMetadata(videoEl));
+		const audioEl = container.querySelector<HTMLAudioElement>(
+			'[data-testid="preview-audio-track-trk"]',
+		);
+		if (!audioEl) throw new Error("no track <audio>");
+		return { video, audioEl, audio: driveAudioEl(audioEl) };
+	}
+
+	it("mounts one <audio> per track with the asset's URL", () => {
+		const { audioEl } = mountWithAudio();
+		expect(audioEl.getAttribute("src")).toBe("file:///tmp/vo.mp3");
+	});
+
+	it("plays inside the window at the trim-offset source time, pauses outside", () => {
+		const { video, audioEl, audio } = mountWithAudio();
+		video.play();
+		// virtualTime lands one tick after the video seek, and the audio loop reads
+		// last frame's virtualTime, so two ticks settle the decision.
+		video.seekTo(3); // virtual 3 → 1s into the 2..4 span
+		tick();
+		tick();
+		expect(audioEl.play).toHaveBeenCalled();
+		expect(audio.currentTime).toBeCloseTo(2, 1); // trimStart 1 + 1s in
+
+		video.seekTo(5); // virtual 5 → past the window end (4)
+		tick();
+		tick();
+		expect(audioEl.pause).toHaveBeenCalled();
+	});
+});
diff --git a/src/components/ai-edition/VirtualPreview.tsx b/src/components/ai-edition/VirtualPreview.tsx
index 804cfa5a5..b0d6d0685 100644
--- a/src/components/ai-edition/VirtualPreview.tsx
+++ b/src/components/ai-edition/VirtualPreview.tsx
@@ -5,7 +5,12 @@ import {
 	MAX_NATIVE_PLAYBACK_RATE,
 } from "@/components/video-editor/types";
 import { resolvePlaybackSegments } from "@/lib/ai-edition/document/timeline";
-import type { AxcutClip, AxcutTrimRange, AxcutZoomRegion } from "@/lib/ai-edition/schema";
+import type {
+	AxcutAudioTrack,
+	AxcutClip,
+	AxcutTrimRange,
+	AxcutZoomRegion,
+} from "@/lib/ai-edition/schema";
 import { audioGainScalar } from "@/lib/ai-edition/store/editorSettings";
 import { useEditorSettings } from "@/lib/ai-edition/store/useEditorSettings";
 import type { PlaybackClockRef } from "@/lib/ai-edition/timeline/playback-clock";
@@ -65,6 +70,32 @@ export function resolveAudioTrackPlayback(
 	};
 }
 
+/**
+ * Where an imported audio track (issue #350) should sit against the RAW virtual
+ * timeline clock, and whether it should be playing there.
+ *
+ * A track occupies `[timelineStartSec, timelineStartSec + (trimEnd - trimStart)]`
+ * on the timeline; its source position is `trimStart` plus however far the
+ * playhead is into that span. Outside the span — or when muted — it parks at the
+ * nearer trim edge and stays paused, the same discipline `resolveAudioTrackPlayback`
+ * uses so the rAF never seeks an element into nothing.
+ *
+ * This is the RAW/document timeline the ruler, playhead and lane all use — NOT
+ * the trim-compressed output timeline — because that is where the track was
+ * placed (`useTimeline.addAudioTrack` seeds `timelineStartSec` from the playhead).
+ * The export mixes on the same RAW positions (see audio.rs), so the two agree.
+ */
+export function resolveTimelineAudioPlayback(virtualTimeSec: number, track: AxcutAudioTrack) {
+	const trimStart = Math.max(0, track.trimStartSec);
+	const trimEnd = track.trimEndSec ?? track.durationSec;
+	const windowLen = Math.max(0, trimEnd - trimStart);
+	const local = virtualTimeSec - track.timelineStartSec;
+	return {
+		targetTimeSec: Math.min(Math.max(trimStart, trimStart + local), trimEnd),
+		shouldPlay: !track.mute && local >= 0 && local < windowLen,
+	};
+}
+
 export interface PreviewAudioGraph {
 	context: AudioContext;
 	gain: GainNode;
@@ -112,6 +143,11 @@ function findNextClipByTimelineOrder(
 
 interface VirtualPreviewProps {
 	videoSources: VideoSource[];
+	/** Imported audio tracks to mix over the video (issue #350), and the file URLs
+	 *  their assets resolve to (keyed by assetId in `id`). Both default to empty, so
+	 *  a project with no imported audio behaves exactly as before. */
+	audioTracks?: AxcutAudioTrack[];
+	audioSources?: VideoSource[];
 	clips: AxcutClip[];
 	zoomRegions?: AxcutZoomRegion[];
 	speedRegions?: SpeedRegion[];
@@ -156,6 +192,8 @@ interface VirtualPreviewProps {
 
 export function VirtualPreview({
 	videoSources,
+	audioTracks = [],
+	audioSources = [],
 	clips,
 	zoomRegions = [],
 	speedRegions = [],
@@ -426,6 +464,17 @@ export function VirtualPreview({
 	virtualDurationSecRef.current = virtualDurationSec;
 	const speedRegionsRef = useRef(speedRegions);
 	speedRegionsRef.current = speedRegions;
+	// Imported audio tracks (issue #350): the rAF reads these through refs, same as
+	// everything else it touches, so a track added/edited mid-playback is picked up
+	// without re-creating the loop. `audioTrackElsRef` maps a track id to its mounted
+	// <audio> element (registered by the ref callback on render).
+	const audioTracksRef = useRef(audioTracks);
+	audioTracksRef.current = audioTracks;
+	const audioTrackElsRef = useRef<Map<string, HTMLAudioElement>>(new Map());
+	const registerAudioTrackEl = useCallback((trackId: string, element: HTMLAudioElement | null) => {
+		if (element) audioTrackElsRef.current.set(trackId, element);
+		else audioTrackElsRef.current.delete(trackId);
+	}, []);
 	// Same reasoning as `clipsRef` above, for the one thing the rAF calls rather than reads:
 	// `seekToVirtualTime` is a `useCallback` whose deps include `clips`, so it takes a new
 	// identity on every clip mutation — a REORDER included. The rAF below is deliberately
@@ -471,6 +520,33 @@ export function VirtualPreview({
 					audio.pause();
 				}
 			}
+			// Imported audio tracks (issue #350): position each against the RAW
+			// virtual timeline it was placed on, play it only inside its window, and
+			// set its level from the track gain × the global output gain. Using
+			// `.volume` rather than a WebAudio node keeps the delicate
+			// primary/supplemental graph untouched; a boost past 0 dB clamps in the
+			// preview (volume maxes at 1) but is still written to the export.
+			const globalGain = audioGainScalar(audioGainDbRef.current);
+			for (const track of audioTracksRef.current) {
+				const el = audioTrackElsRef.current.get(track.id);
+				if (!el) continue;
+				const trackTarget = resolveTimelineAudioPlayback(virtualTimeSecRef.current, track);
+				if (el.playbackRate !== v.playbackRate) el.playbackRate = v.playbackRate;
+				el.volume = Math.min(1, audioGainScalar(track.gainDb) * globalGain);
+				if (Math.abs(el.currentTime - trackTarget.targetTimeSec) > 0.025) {
+					try {
+						el.currentTime = trackTarget.targetTimeSec;
+					} catch {
+						// media metadata not ready yet
+					}
+				}
+				if (!v.paused && trackTarget.shouldPlay && el.paused) {
+					const playback = el.play();
+					if (playback) void playback.catch(() => undefined);
+				} else if ((v.paused || !trackTarget.shouldPlay) && !el.paused) {
+					el.pause();
+				}
+			}
 			// Publish this frame's live position/rate for other media elements
 			// (webcam) to read directly — see playback-clock.ts for why this
 			// bypasses React state entirely.
@@ -1146,6 +1222,23 @@ export function VirtualPreview({
 								data-testid="preview-audio-supplemental"
 							/>
 						) : null}
+						{/* Imported audio tracks (issue #350). One element per track, kept in
+						    sync by the rAF loop above via audioTrackElsRef. A track whose asset
+						    URL isn't resolved yet is skipped rather than mounted src-less. */}
+						{audioTracks.map((track) => {
+							const src = audioSources.find((s) => s.id === track.assetId)?.src;
+							if (!src) return null;
+							return (
+								<audio
+									key={`audio-track:${track.id}`}
+									ref={(element) => registerAudioTrackEl(track.id, element)}
+									src={src}
+									preload="metadata"
+									aria-hidden="true"
+									data-testid={`preview-audio-track-${track.id}`}
+								/>
+							);
+						})}
 						{/* Plus d'overlay ici du tout. « Loading preview… » reflétait l'état du
 						    <video> CACHÉ (source horloge/audio), pas la preview RÉELLE — le canvas
 						    natif, qui montre déjà une image valide pendant que le <video> re-seek.

From 79efff1f35a6c22ed5f86bb330d026b6d4489d95 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 09:45:28 +0200
Subject: [PATCH 07/20] feat(export): mix imported audio tracks into the
 exported MP4
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Phase 6 of issue #350 — imported audio now lands in the export, not just the
preview. The native compositor mixes each track over the assembled programme.

- audio.rs::mix_external_tracks overlays each track between
  assemble_concatenated_pcm and finish_audio: its trim window is decoded
  through the same decode_clip_audio path a clip's audio uses (48 kHz stereo),
  scaled by the per-track gain (the same 10^(dB/20) law as finish_audio), and
  summed in at its startSec offset. A track past the video end is truncated so
  audio and video stay the same length. The placement/gain/clamp math is split
  into overlay_track_pcm and unit-tested without ffmpeg (cargo test, verified
  on Linux).
- scene.rs gains SceneAudioTrack + Scene.audio_tracks (a separate field, so
  SceneAudio stays Copy and the pipelines keep copying it out of a borrow).
  Wired into all three pipeline_{linux,macos,windows}.rs.
- buildSceneDescription resolves each track to { path, startSec, gainDb,
  trimStartSec, trimEndSec, mute }. startSec is the raw timeline position —
  exact without trims/speed, an accepted approximation otherwise (the preview
  approximates trims the same way); trimEndSec is always concrete (the
  compositor preallocates the decode window from it). resolveSceneAssetPaths
  round-trips the JSON so the new field reaches the addon untouched.
- Corrected the Phase 1 schema comment (tracks live on the RAW timeline, not
  output time) and documented the mix step in export-pipeline.md.

Verified: compositor builds + `cargo test --lib audio` (14) pass on Linux;
tsc (app+test), biome, and the scene-description tests (95) pass. NOT yet
verified: the addon (.node) must be rebuilt with build:native:compositor:linux
and an actual export listened to — the manual E2E this phase requires.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 crates/compositor/src/audio.rs                | 119 +++++++++++++++++-
 crates/compositor/src/pipeline_linux.rs       |  13 +-
 crates/compositor/src/pipeline_macos.rs       |  12 +-
 crates/compositor/src/pipeline_windows.rs     |   9 +-
 crates/compositor/src/scene.rs                |  29 +++++
 src/lib/ai-edition/schema/index.ts            |  21 ++--
 src/native/sceneDescription.test.ts           |  54 ++++++++
 src/native/sceneDescription.ts                |  37 ++++++
 .../architecture/export-pipeline.md           |  13 ++
 9 files changed, 292 insertions(+), 15 deletions(-)

diff --git a/crates/compositor/src/audio.rs b/crates/compositor/src/audio.rs
index db9b46e13..ddd809bbd 100644
--- a/crates/compositor/src/audio.rs
+++ b/crates/compositor/src/audio.rs
@@ -4,7 +4,7 @@
 
 use crate::ffi::*;
 use crate::regions::SpeedSegment;
-use crate::scene::SceneAudio;
+use crate::scene::{SceneAudio, SceneAudioTrack};
 use anyhow::{bail, Result};
 use std::f32::consts::PI;
 use std::ffi::CString;
@@ -914,6 +914,71 @@ pub fn assemble_concatenated_pcm(
     output
 }
 
+/// Mix imported audio tracks (issue #350) over the assembled programme.
+///
+/// Each track is decoded across its trim window — already resampled to 48 kHz
+/// stereo by `decode_clip_audio`, the same path a clip's own audio takes — scaled
+/// by its per-track gain (the same `10^(dB/20)` law as `finish_audio`), and summed
+/// into the programme at `start_sec`. The programme length is NOT extended: a
+/// track that runs past the video is truncated to it, so the audio and video
+/// streams stay the same length for the muxer.
+///
+/// A muted track, or one whose file has no decodable audio, is skipped — the same
+/// degradation a stream-less clip gets. `trim_end_sec` must be concrete (the
+/// renderer sends `trimEnd ?? durationSec`): `decode_clip_audio` preallocates from
+/// it, so an unbounded end would try to allocate the whole real line.
+pub fn mix_external_tracks(mut programme: PlanarPcm, tracks: &[SceneAudioTrack]) -> PlanarPcm {
+    let programme_len = programme.first().map(Vec::len).unwrap_or(0);
+    if programme_len == 0 {
+        return programme;
+    }
+    for track in tracks {
+        if track.mute {
+            continue;
+        }
+        let trim_start = track.trim_start_sec.max(0.0);
+        let Some(trim_end) = track.trim_end_sec else {
+            // Without a concrete end there is no safe window to decode (see the doc
+            // comment); the renderer always resolves one, so this only guards a
+            // hand-written scene.
+            continue;
+        };
+        if trim_end <= trim_start {
+            continue;
+        }
+        let decoded = match decode_clip_audio(&track.path, trim_start, trim_end) {
+            Ok(Some(pcm)) => pcm,
+            _ => continue,
+        };
+        let gain = 10.0f32.powf(track.gain_db.clamp(-12.0, 12.0) / 20.0);
+        let offset = (track.start_sec.max(0.0) * AUDIO_OUTPUT_SAMPLE_RATE as f64).round() as usize;
+        overlay_track_pcm(&mut programme, &decoded, offset, gain);
+    }
+    programme
+}
+
+/// Sum one decoded track into the programme at `offset` samples, scaled by `gain`,
+/// truncated at the programme's end. Split out of `mix_external_tracks` so the
+/// placement/gain/clamp math is testable without ffmpeg, exactly like
+/// `mix_aligned_tracks` is split from the decode above.
+fn overlay_track_pcm(programme: &mut PlanarPcm, decoded: &PlanarPcm, offset: usize, gain: f32) {
+    let programme_len = programme.first().map(Vec::len).unwrap_or(0);
+    if offset >= programme_len {
+        return;
+    }
+    let room = programme_len - offset;
+    for channel in 0..AUDIO_OUTPUT_CHANNELS {
+        let Some(source) = decoded.get(channel) else {
+            continue;
+        };
+        let count = source.len().min(room);
+        let dst = &mut programme[channel];
+        for k in 0..count {
+            dst[offset + k] += source[k] * gain;
+        }
+    }
+}
+
 /// Encodeur AAC attaché au muxer avant son header. Les paquets utilisent le même interleaver
 /// que la vidéo ; les pts restent en unités échantillon jusqu'au rescale vers l'AVStream.
 pub(crate) struct AacEncoder {
@@ -1044,6 +1109,58 @@ mod tests {
         assert_eq!(mixed[1], vec![0.25, -0.5, 0.75]);
     }
 
+    // Imported audio track overlay (issue #350).
+    #[test]
+    fn overlay_sums_at_offset_with_gain() {
+        let mut programme = planar(&[0.1, 0.1, 0.1, 0.1]);
+        // ×2 gain, placed at sample offset 1.
+        overlay_track_pcm(&mut programme, &planar(&[0.2, 0.2]), 1, 2.0);
+        assert_eq!(programme[0], vec![0.1, 0.5, 0.5, 0.1]);
+        assert_eq!(programme[1], vec![0.1, 0.5, 0.5, 0.1]);
+    }
+
+    #[test]
+    fn overlay_truncates_a_track_that_runs_past_the_programme() {
+        let mut programme = planar(&[0.0, 0.0, 0.0]);
+        // A 4-sample track placed at offset 2 has room for only 1 sample.
+        overlay_track_pcm(&mut programme, &planar(&[1.0, 1.0, 1.0, 1.0]), 2, 1.0);
+        assert_eq!(programme[0], vec![0.0, 0.0, 1.0]);
+    }
+
+    #[test]
+    fn overlay_past_the_end_is_a_no_op() {
+        let mut programme = planar(&[0.3, 0.3]);
+        overlay_track_pcm(&mut programme, &planar(&[1.0]), 5, 1.0);
+        assert_eq!(programme[0], vec![0.3, 0.3]);
+    }
+
+    #[test]
+    fn mix_external_tracks_skips_muted_and_empty_windows() {
+        let programme = planar(&[0.4, 0.4]);
+        let tracks = vec![
+            SceneAudioTrack {
+                path: "/nope.mp3".into(),
+                start_sec: 0.0,
+                gain_db: 0.0,
+                trim_start_sec: 0.0,
+                trim_end_sec: Some(1.0),
+                mute: true,
+            },
+            SceneAudioTrack {
+                path: "/nope.mp3".into(),
+                start_sec: 0.0,
+                gain_db: 0.0,
+                trim_start_sec: 2.0,
+                trim_end_sec: Some(1.0), // end <= start: empty window, never decoded
+                mute: false,
+            },
+        ];
+        // Both tracks are skipped before any decode, so the programme is untouched
+        // even though the path does not exist.
+        let out = mix_external_tracks(programme, &tracks);
+        assert_eq!(out[0], vec![0.4, 0.4]);
+    }
+
     #[test]
     fn single_track_is_not_clamped() {
         // Promesse de non-régression : une source mono-piste ressort telle quelle, y compris
diff --git a/crates/compositor/src/pipeline_linux.rs b/crates/compositor/src/pipeline_linux.rs
index 910738fc0..8d35c0291 100644
--- a/crates/compositor/src/pipeline_linux.rs
+++ b/crates/compositor/src/pipeline_linux.rs
@@ -22,7 +22,7 @@ use std::ptr;
 
 use crate::audio::{
     assemble_concatenated_pcm, build_audio_concat_plan, decode_clip_audio, finish_audio,
-    stretch_clip_pcm_by_speed, AacEncoder, PlanarPcm,
+    mix_external_tracks, stretch_clip_pcm_by_speed, AacEncoder, PlanarPcm,
 };
 use crate::config::Cfg;
 use crate::d3d::Gpu;
@@ -458,6 +458,12 @@ pub fn run_composited_multi(
 
     let scene = comp.scene_snapshot();
     let audio_settings = scene.as_ref().map(|scene| scene.audio).unwrap_or_default();
+    // Imported audio tracks (issue #350), cloned out of the borrowed scene so the
+    // mix step below owns them. Empty for a project with no imported audio.
+    let audio_tracks = scene
+        .as_ref()
+        .map(|scene| scene.audio_tracks.clone())
+        .unwrap_or_default();
     // Ring de staging a 2 : l'export ne veut que du debit, une frame de latence
     // ne se voit pas dans un fichier. Voir `Compositor::set_readback_depth` pour
     // la raison pour laquelle la preview, elle, reste a 1.
@@ -535,7 +541,10 @@ pub fn run_composited_multi(
         let declared_audio: Vec<bool> = clips.iter().map(|c| c.has_audio).collect();
         let plan = build_audio_concat_plan(&clip_frame_counts, &declared_audio, out_fps as f64);
         audio_encoder.encode(
-            &finish_audio(assemble_concatenated_pcm(&clip_pcm, &plan), audio_settings),
+            &finish_audio(
+                mix_external_tracks(assemble_concatenated_pcm(&clip_pcm, &plan), &audio_tracks),
+                audio_settings,
+            ),
             octx,
         )?;
         crate::ffi::averr(crate::ffi::av_write_trailer(octx), "write_trailer")?;
diff --git a/crates/compositor/src/pipeline_macos.rs b/crates/compositor/src/pipeline_macos.rs
index 10de3fac2..1a3ebb9c7 100644
--- a/crates/compositor/src/pipeline_macos.rs
+++ b/crates/compositor/src/pipeline_macos.rs
@@ -31,7 +31,7 @@
 
 use crate::audio::{
     assemble_concatenated_pcm, build_audio_concat_plan, decode_clip_audio, finish_audio,
-    stretch_clip_pcm_by_speed, AacEncoder, PlanarPcm,
+    mix_external_tracks, stretch_clip_pcm_by_speed, AacEncoder, PlanarPcm,
 };
 use crate::compositor::Compositor;
 use crate::d3d::Gpu;
@@ -1077,6 +1077,11 @@ pub fn run_composited_multi(
     // raconte avoir déjà coûté une fois.
     let scene = comp.scene_snapshot();
     let audio_settings = scene.as_ref().map(|scene| scene.audio).unwrap_or_default();
+    // Imported audio tracks (issue #350), cloned out of the borrowed scene.
+    let audio_tracks = scene
+        .as_ref()
+        .map(|scene| scene.audio_tracks.clone())
+        .unwrap_or_default();
     frames = unsafe {
         crate::timeline_walk::walk_composited_timeline(
             clips,
@@ -1132,7 +1137,10 @@ pub fn run_composited_multi(
         let declared_audio: Vec<bool> = clips.iter().map(|clip| clip.has_audio).collect();
         let plan = build_audio_concat_plan(&clip_frame_counts, &declared_audio, out_fps as f64);
         audio_encoder.encode(
-            &finish_audio(assemble_concatenated_pcm(&clip_pcm, &plan), audio_settings),
+            &finish_audio(
+                mix_external_tracks(assemble_concatenated_pcm(&clip_pcm, &plan), &audio_tracks),
+                audio_settings,
+            ),
             octx,
         )?;
 
diff --git a/crates/compositor/src/pipeline_windows.rs b/crates/compositor/src/pipeline_windows.rs
index 11738bcd4..01cbda745 100644
--- a/crates/compositor/src/pipeline_windows.rs
+++ b/crates/compositor/src/pipeline_windows.rs
@@ -4,7 +4,7 @@
 
 use crate::audio::{
     assemble_concatenated_pcm, build_audio_concat_plan, decode_clip_audio, finish_audio,
-    stretch_clip_pcm_by_speed, AacEncoder, PlanarPcm,
+    mix_external_tracks, stretch_clip_pcm_by_speed, AacEncoder, PlanarPcm,
 };
 use crate::compositor::{Compositor, OUT_H, OUT_W};
 use crate::config::Cfg;
@@ -1343,6 +1343,11 @@ unsafe fn run_multi_inner(
     // fenêtrage par clip ; `walk_composited_timeline` s'en charge.
     let scene = comp.scene_snapshot();
     let audio_settings = scene.as_ref().map(|scene| scene.audio).unwrap_or_default();
+    // Imported audio tracks (issue #350), cloned out of the borrowed scene.
+    let audio_tracks = scene
+        .as_ref()
+        .map(|scene| scene.audio_tracks.clone())
+        .unwrap_or_default();
 
     // ---- encodeur (choisi à l'exécution, cf. ExportCodec::candidates) + mux ----
     // Backend CPU : pas de pool D3D11 du tout. `av_hwdevice_ctx_init(D3D11VA)` échoue sur
@@ -1467,7 +1472,7 @@ unsafe fn run_multi_inner(
         out_fps as f64,
     );
     let assembled_audio = finish_audio(
-        assemble_concatenated_pcm(&clip_pcm, &audio_plan),
+        mix_external_tracks(assemble_concatenated_pcm(&clip_pcm, &audio_plan), &audio_tracks),
         audio_settings,
     );
     audio_encoder.encode(&assembled_audio, octx)?;
diff --git a/crates/compositor/src/scene.rs b/crates/compositor/src/scene.rs
index 2d20e233b..822e0d5bc 100644
--- a/crates/compositor/src/scene.rs
+++ b/crates/compositor/src/scene.rs
@@ -420,6 +420,31 @@ pub struct SceneAudio {
     pub gain_db: f32,
 }
 
+/// One imported audio track (issue #350) mixed over the assembled programme —
+/// voiceover / BGM / SFX. Deliberately a SEPARATE `Scene` field rather than a
+/// member of `SceneAudio`, so `SceneAudio` stays `Copy` and the pipelines keep
+/// copying it out of a borrow unchanged.
+///
+/// `start_sec` is the track's head on the OUTPUT programme; `trim_start_sec` /
+/// `trim_end_sec` window the source file (both source seconds). The renderer
+/// resolves `start_sec` from the track's raw timeline position — equal to it when
+/// the project has no trims/speed, which is the case this first cut mixes exactly.
+#[derive(Debug, Clone, Default, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SceneAudioTrack {
+    pub path: String,
+    #[serde(default)]
+    pub start_sec: f64,
+    #[serde(default)]
+    pub gain_db: f32,
+    #[serde(default)]
+    pub trim_start_sec: f64,
+    #[serde(default)]
+    pub trim_end_sec: Option<f64>,
+    #[serde(default)]
+    pub mute: bool,
+}
+
 #[derive(Debug, Clone, Copy, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct SceneOutput {
@@ -451,6 +476,10 @@ pub struct Scene {
     /// Global audio finishing. Default keeps old scene payloads bit-for-bit compatible.
     #[serde(default)]
     pub audio: SceneAudio,
+    /// Imported audio tracks mixed over the programme (issue #350). `#[serde(default)]`:
+    /// absent from every scene written before this, and from a project with none.
+    #[serde(default)]
+    pub audio_tracks: Vec<SceneAudioTrack>,
     /// Crop écran par clip, dans le même ordre que `clips` (`cropByClip` côté TS).
     #[serde(default)]
     pub crop_by_clip: Vec<Option<SceneCrop>>,
diff --git a/src/lib/ai-edition/schema/index.ts b/src/lib/ai-edition/schema/index.ts
index 7024b37c4..e2449f44c 100644
--- a/src/lib/ai-edition/schema/index.ts
+++ b/src/lib/ai-edition/schema/index.ts
@@ -477,16 +477,21 @@ export const zoomRegionSchema = endGteStart(
 );
 
 // External audio import (issue #350) — voiceover / BGM / SFX layered over the
-// assembled programme. Unlike zoom/speed/annotation/trim, an audio track is NOT
-// clip-anchored: it floats over the whole timeline, so it is addressed in OUTPUT
-// (post-trim, post-speed) timeline seconds — the same domain the compositor's
-// concatenated programme PCM lives in (see `SceneAudio` in
-// src/native/sceneDescription.ts and `audio.rs`). That single invariant is what
-// keeps the live preview and the export in sync without a per-track sync offset.
+// programme. Unlike zoom/speed/annotation/trim, an audio track is NOT
+// clip-anchored: it floats over the whole timeline, addressed in RAW/document
+// timeline seconds — the same clock the ruler, playhead and clip
+// `timelineStartSec`/`timelineEndSec` use, and the one `addAudioTrack` seeds from
+// the playhead. The preview positions the track on exactly this clock (see
+// `resolveTimelineAudioPlayback` in VirtualPreview). The export's OUTPUT programme
+// is trim-compressed, so the renderer maps this position to output time when
+// building the scene — an identity map when the project has no trims/speed (the
+// common case), an accepted approximation otherwise, the same way the preview
+// approximates trims by re-seeking. See `SceneAudioTrack` (sceneDescription.ts,
+// audio.rs).
 //
 // `assetId` points at an asset with `kind: "audio"`. `timelineStartSec` places
-// the track's head on the programme; `trimStartSec`/`trimEndSec` window the
-// source file (both in source seconds); `gainDb` + `mute` set its level.
+// the track's head; `trimStartSec`/`trimEndSec` window the source file (both in
+// source seconds); `gainDb` + `mute` set its level.
 export const audioTrackSchema = z
 	.object({
 		id: z.string().min(1),
diff --git a/src/native/sceneDescription.test.ts b/src/native/sceneDescription.test.ts
index 2c02137e0..0802f8d60 100644
--- a/src/native/sceneDescription.test.ts
+++ b/src/native/sceneDescription.test.ts
@@ -1789,3 +1789,57 @@ describe("buildSceneDescription.captions", () => {
 		expect(text?.color).toBe("#ffffff");
 	});
 });
+
+// --- imported audio tracks (issue #350) ------------------------------------
+describe("buildSceneDescription.audioTracks", () => {
+	const audioAsset = makeAsset({
+		id: "aud",
+		kind: "audio",
+		originalPath: "/music.mp3",
+		durationSec: 30,
+	});
+	const track = {
+		id: "trk1",
+		assetId: "aud",
+		timelineStartSec: 5,
+		durationSec: 30,
+		trimStartSec: 2,
+		trimEndSec: 12 as number | undefined,
+		gainDb: -3,
+		mute: false,
+		label: "",
+	};
+
+	it("maps a track to the mix list with its resolved path and window", () => {
+		const doc = makeDoc({ assets: [audioAsset], audioTracks: [track] });
+		expect(buildSceneDescription(doc).audioTracks).toEqual([
+			{
+				path: "/music.mp3",
+				startSec: 5,
+				gainDb: -3,
+				trimStartSec: 2,
+				trimEndSec: 12,
+				mute: false,
+			},
+		]);
+	});
+
+	it("resolves the trim-out to the source duration when the tail isn't trimmed", () => {
+		const doc = makeDoc({
+			assets: [audioAsset],
+			audioTracks: [{ ...track, trimEndSec: undefined }],
+		});
+		// trimEndSec must be concrete for the compositor; falls back to durationSec.
+		expect(buildSceneDescription(doc).audioTracks[0]?.trimEndSec).toBe(30);
+	});
+
+	it("drops a track whose asset has no resolvable path", () => {
+		const doc = makeDoc({ assets: [], audioTracks: [track] });
+		expect(buildSceneDescription(doc).audioTracks).toEqual([]);
+	});
+
+	it("is empty for a project with no imported audio", () => {
+		const doc = makeDoc({ assets: [makeAsset({ id: "a", originalPath: "/a.mp4" })] });
+		expect(buildSceneDescription(doc).audioTracks).toEqual([]);
+	});
+});
diff --git a/src/native/sceneDescription.ts b/src/native/sceneDescription.ts
index 38408631c..3d1100ad6 100644
--- a/src/native/sceneDescription.ts
+++ b/src/native/sceneDescription.ts
@@ -391,6 +391,23 @@ export interface SceneDescription {
 	audio: {
 		gainDb: number;
 	};
+	/**
+	 * Imported audio tracks (issue #350), mixed over the assembled programme by
+	 * `audio::mix_external_tracks`. `startSec` is the head on the OUTPUT programme;
+	 * it equals the track's raw timeline position, which is exact when the project
+	 * has no trims/speed and an accepted approximation otherwise (the preview
+	 * approximates the same way). `trimEndSec` is always concrete — the compositor
+	 * preallocates the decode window from it — so it is resolved to the source
+	 * duration when the track's tail isn't trimmed.
+	 */
+	audioTracks: Array<{
+		path: string;
+		startSec: number;
+		gainDb: number;
+		trimStartSec: number;
+		trimEndSec: number;
+		mute: boolean;
+	}>;
 	/**
 	 * Per-clip screen crop (fractions of the frame), or null for the identity
 	 * (full-frame) crop. One entry per clip in the same order as `clips`, so a
@@ -449,6 +466,25 @@ export function buildSceneDescription(
 	const settings = getEditorSettings(document);
 
 	const assetById = new Map(document.assets.map((a) => [a.id, a]));
+	// Imported audio tracks (issue #350) → the compositor's mix list. Resolve the
+	// asset's file path and a concrete trim-out (the source duration when the tail
+	// isn't trimmed — the compositor preallocates its decode window from it). A
+	// track whose asset or path is missing is dropped rather than sent path-less.
+	const audioTracks = document.audioTracks.flatMap((track) => {
+		const asset = assetById.get(track.assetId);
+		if (!asset?.originalPath) return [];
+		const trimEndSec = track.trimEndSec ?? asset.durationSec ?? track.durationSec;
+		return [
+			{
+				path: asset.originalPath,
+				startSec: track.timelineStartSec,
+				gainDb: track.gainDb,
+				trimStartSec: track.trimStartSec,
+				trimEndSec,
+				mute: track.mute,
+			},
+		];
+	});
 	const visibleClips = resolveVisibleClips(document);
 	const clips: CompositorClipInput[] = visibleClips.flatMap((clip) => {
 		const asset = assetById.get(clip.assetId);
@@ -783,6 +819,7 @@ export function buildSceneDescription(
 		audio: {
 			gainDb: settings.audioGainDb,
 		},
+		audioTracks,
 		background: parseWallpaper(settings.wallpaper),
 		zoomRegions: projectedZoomRegions.map((region) => ({
 			id: region.id,
diff --git a/technical-documentation/architecture/export-pipeline.md b/technical-documentation/architecture/export-pipeline.md
index 0068fdf4c..06bc092bb 100644
--- a/technical-documentation/architecture/export-pipeline.md
+++ b/technical-documentation/architecture/export-pipeline.md
@@ -74,6 +74,19 @@ and **one** encoder + muxer pair:
   The WSOLA stretch is kicked off before the video loop so it overlaps
   the encode and does not add to the wall.
 
+- **Imported audio tracks** (voiceover / BGM / SFX, issue #350) are mixed
+  on top of the assembled programme by `audio.rs::mix_external_tracks`,
+  between `assemble_concatenated_pcm` and `finish_audio`. Each track's
+  trim window is decoded through the same `decode_clip_audio` path a clip
+  uses, scaled by its per-track gain, and summed in at its `startSec`
+  offset; a track running past the video is truncated to it so the two
+  streams stay the same length. `startSec` is resolved renderer-side
+  (`buildSceneDescription`) from the track's raw timeline position — an
+  identity map without trims/speed, an accepted approximation otherwise,
+  matching how the preview approximates trims by re-seeking. The CLI's
+  `openscreen export --audio` remains a separate post-export remux
+  (`voiceoverMix.ts`) for a single track and is unaffected.
+
 - **Output** honours the timeline's selected aspect ratio
   (`resolveAspectRatioValue` over `getEditorSettings(document).aspectRatio` —
   the same typed façade `buildSceneDescription` reads, so the dialog cannot

From 5310b281e947ed4129f4a95d96332a4fd0418887 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 10:41:50 +0200
Subject: [PATCH 08/20] feat(editor): fold audio import into the single "Import
 media" button
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Addresses review feedback on #350: a separate "Import audio" button was
both undiscoverable (added to only one of three media surfaces) and worse
UX than just letting "Import media" take audio too.

- open-video-file-picker is now a combined media picker: it offers video AND
  audio, approves whichever was chosen (video path first, then audio), and
  returns `kind` so the renderer routes an audio file to importAudioAsset
  (asset + timeline track) and a video file to addAsset (clip).
- All three import surfaces route by kind: MediaStage (the main media view),
  MediaPane (chat side panel), and EditorEmptyState. The standalone "Import
  audio" button and its handler are removed.
- Dropped the now-dead open-audio-file-picker IPC, its preload method/type,
  and the importAudio / couldNotAddAudio / selectAudio strings; added a
  mediaFiles dialog string across all 13 locales. approveReadableAudioPath
  and the audio extension set stay — the combined picker uses them.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 electron/electron-env.d.ts                    | 11 +--
 electron/ipc/handlers.ts                      | 83 ++++++++-----------
 electron/preload.ts                           |  3 -
 .../ai-edition/EditorEmptyState.tsx           | 10 ++-
 src/components/ai-edition/LeftPanel.tsx       | 51 ++----------
 src/components/ai-edition/v4/MediaStage.tsx   |  6 +-
 src/i18n/locales/ar/dialogs.json              |  2 +-
 src/i18n/locales/ar/editor.json               |  4 +-
 src/i18n/locales/en/dialogs.json              |  3 +-
 src/i18n/locales/en/editor.json               |  2 -
 src/i18n/locales/es/dialogs.json              |  2 +-
 src/i18n/locales/es/editor.json               |  4 +-
 src/i18n/locales/fr/dialogs.json              |  2 +-
 src/i18n/locales/fr/editor.json               |  4 +-
 src/i18n/locales/it/dialogs.json              |  2 +-
 src/i18n/locales/it/editor.json               |  4 +-
 src/i18n/locales/ja-JP/dialogs.json           |  2 +-
 src/i18n/locales/ja-JP/editor.json            |  4 +-
 src/i18n/locales/ko-KR/dialogs.json           |  2 +-
 src/i18n/locales/ko-KR/editor.json            |  4 +-
 src/i18n/locales/pt-BR/dialogs.json           |  2 +-
 src/i18n/locales/pt-BR/editor.json            |  4 +-
 src/i18n/locales/ru/dialogs.json              |  2 +-
 src/i18n/locales/ru/editor.json               |  4 +-
 src/i18n/locales/tr/dialogs.json              |  2 +-
 src/i18n/locales/tr/editor.json               |  4 +-
 src/i18n/locales/vi/dialogs.json              |  2 +-
 src/i18n/locales/vi/editor.json               |  4 +-
 src/i18n/locales/zh-CN/dialogs.json           |  2 +-
 src/i18n/locales/zh-CN/editor.json            |  4 +-
 src/i18n/locales/zh-TW/dialogs.json           |  2 +-
 src/i18n/locales/zh-TW/editor.json            |  4 +-
 32 files changed, 80 insertions(+), 161 deletions(-)

diff --git a/electron/electron-env.d.ts b/electron/electron-env.d.ts
index 852e76319..8bd505bb9 100644
--- a/electron/electron-env.d.ts
+++ b/electron/electron-env.d.ts
@@ -278,22 +278,17 @@ interface Window {
 			message?: string;
 			error?: string;
 		}>;
+		// "Import media" — video or audio (issue #350). `kind` says which was picked
+		// so the caller routes an audio file to an audio asset+track.
 		openVideoFilePicker: () => Promise<{
 			success: boolean;
 			path?: string;
+			kind?: "video" | "audio";
 			// Browser-mode shim only: a blob: URL has no meaningful basename, so
 			// the shim carries the picked File's real name here for the label.
 			name?: string;
 			canceled?: boolean;
 		}>;
-		// Import an external audio file (voiceover / BGM / SFX) — issue #350.
-		openAudioFilePicker: () => Promise<{
-			success: boolean;
-			path?: string;
-			name?: string;
-			canceled?: boolean;
-			message?: string;
-		}>;
 		setCurrentVideoPath: (path: string) => Promise<{ success: boolean }>;
 		setCurrentRecordingSession: (
 			session: import("../src/lib/recordingSession").RecordingSession | null,
diff --git a/electron/ipc/handlers.ts b/electron/ipc/handlers.ts
index 1edee583f..d0d43b27a 100644
--- a/electron/ipc/handlers.ts
+++ b/electron/ipc/handlers.ts
@@ -3610,6 +3610,10 @@ export function registerIpcHandlers(
 		}
 	});
 
+	// "Import media" (issue #350): one picker for video AND audio. It offers both
+	// extension sets and approves whichever the pick is, returning `kind` so the
+	// renderer routes an audio file to an audio asset+track and a video file to a
+	// clip. Keeps its historical name so every existing caller keeps working.
 	ipcMain.handle("open-video-file-picker", async () => {
 		try {
 			const dialogOptions = buildDialogOptions(
@@ -3617,55 +3621,31 @@ export function registerIpcHandlers(
 					title: mainT("dialogs", "fileDialogs.selectVideo"),
 					defaultPath: RECORDINGS_DIR,
 					filters: [
+						{
+							name: mainT("dialogs", "fileDialogs.mediaFiles"),
+							extensions: [
+								"webm",
+								"mp4",
+								"mov",
+								"avi",
+								"mkv",
+								"m4v",
+								"wmv",
+								"flv",
+								"ts",
+								"mp3",
+								"wav",
+								"m4a",
+								"aac",
+								"flac",
+								"ogg",
+								"opus",
+							],
+						},
 						{
 							name: mainT("dialogs", "fileDialogs.videoFiles"),
 							extensions: ["webm", "mp4", "mov", "avi", "mkv", "m4v", "wmv", "flv", "ts"],
 						},
-						{ name: mainT("dialogs", "fileDialogs.allFiles"), extensions: ["*"] },
-					],
-					properties: ["openFile"],
-				},
-				getMainWindow(),
-			);
-			const result = await dialog.showOpenDialog(dialogOptions);
-
-			if (result.canceled || result.filePaths.length === 0) {
-				return { success: false, canceled: true };
-			}
-
-			const normalizedPath = await approveReadableVideoPath(result.filePaths[0]);
-			if (!normalizedPath) {
-				return {
-					success: false,
-					message: "Selected file is not a supported readable video file",
-				};
-			}
-
-			currentProjectPath = null;
-			return {
-				success: true,
-				path: normalizedPath,
-			};
-		} catch (error) {
-			console.error("Failed to open file picker:", error);
-			return {
-				success: false,
-				message: "Failed to open file picker",
-				error: String(error),
-			};
-		}
-	});
-
-	// Import an external audio file (voiceover / BGM / SFX) — issue #350. Mirrors
-	// the video picker but approves against the audio extension set; the returned
-	// path is added to the project as a `kind: "audio"` asset by the renderer.
-	ipcMain.handle("open-audio-file-picker", async () => {
-		try {
-			const dialogOptions = buildDialogOptions(
-				{
-					title: mainT("dialogs", "fileDialogs.selectAudio"),
-					defaultPath: RECORDINGS_DIR,
-					filters: [
 						{
 							name: mainT("dialogs", "fileDialogs.audioFiles"),
 							extensions: ["mp3", "wav", "m4a", "aac", "flac", "ogg", "opus"],
@@ -3682,23 +3662,28 @@ export function registerIpcHandlers(
 				return { success: false, canceled: true };
 			}
 
-			const normalizedPath = await approveReadableAudioPath(result.filePaths[0]);
+			// Try video first, then audio — the extension gate is the only difference,
+			// and the two sets don't overlap, so at most one approves.
+			const videoPath = await approveReadableVideoPath(result.filePaths[0]);
+			const normalizedPath = videoPath ?? (await approveReadableAudioPath(result.filePaths[0]));
 			if (!normalizedPath) {
 				return {
 					success: false,
-					message: "Selected file is not a supported readable audio file",
+					message: "Selected file is not a supported readable media file",
 				};
 			}
 
+			currentProjectPath = null;
 			return {
 				success: true,
 				path: normalizedPath,
+				kind: videoPath ? ("video" as const) : ("audio" as const),
 			};
 		} catch (error) {
-			console.error("Failed to open audio file picker:", error);
+			console.error("Failed to open file picker:", error);
 			return {
 				success: false,
-				message: "Failed to open audio file picker",
+				message: "Failed to open file picker",
 				error: String(error),
 			};
 		}
diff --git a/electron/preload.ts b/electron/preload.ts
index 16227f110..6aff16407 100644
--- a/electron/preload.ts
+++ b/electron/preload.ts
@@ -276,9 +276,6 @@ contextBridge.exposeInMainWorld("electronAPI", {
 	openVideoFilePicker: () => {
 		return ipcRenderer.invoke("open-video-file-picker");
 	},
-	openAudioFilePicker: () => {
-		return ipcRenderer.invoke("open-audio-file-picker");
-	},
 	setCurrentVideoPath: (path: string) => {
 		return ipcRenderer.invoke("set-current-video-path", path);
 	},
diff --git a/src/components/ai-edition/EditorEmptyState.tsx b/src/components/ai-edition/EditorEmptyState.tsx
index 226171dca..6daec79be 100644
--- a/src/components/ai-edition/EditorEmptyState.tsx
+++ b/src/components/ai-edition/EditorEmptyState.tsx
@@ -47,6 +47,7 @@ export function EditorEmptyState({
 
 	const createProject = useProjectStore((s) => s.createProject);
 	const addAsset = useProjectStore((s) => s.addAsset);
+	const importAudioAsset = useProjectStore((s) => s.importAudioAsset);
 	const loadProject = useProjectStore((s) => s.loadProject);
 
 	const ensureProject = useCallback(async (): Promise<string | null> => {
@@ -63,14 +64,17 @@ export function EditorEmptyState({
 			const projectId = await ensureProject();
 			if (!projectId) return;
 			const label = result.name || result.path.split(/[\\/]/).pop() || "Recording";
-			await addAsset(result.path, label);
+			// The picker imports media (issue #350): audio lands as a kind:"audio"
+			// asset + track, video as a clip.
+			if (result.kind === "audio") await importAudioAsset(result.path, label);
+			else await addAsset(result.path, label);
 		} catch (err) {
 			setDropError("load-failed");
 			// ponytail: surface as a console message only — the dialog above
 			// already tells the user something went wrong.
-			console.error("Failed to import video", err);
+			console.error("Failed to import media", err);
 		}
-	}, [addAsset, ensureProject]);
+	}, [addAsset, importAudioAsset, ensureProject]);
 
 	// A loaded project JSON is either a current AxcutDocument (has its own
 	// `schemaVersion`) or a legacy EditorProjectData that must be migrated.
diff --git a/src/components/ai-edition/LeftPanel.tsx b/src/components/ai-edition/LeftPanel.tsx
index 3b237326a..3b0836d87 100644
--- a/src/components/ai-edition/LeftPanel.tsx
+++ b/src/components/ai-edition/LeftPanel.tsx
@@ -1,14 +1,4 @@
-import {
-	ArrowLeft,
-	Check,
-	Film,
-	Loader2,
-	MessageSquare,
-	Music,
-	Plus,
-	Search,
-	X,
-} from "lucide-react";
+import { ArrowLeft, Check, Film, Loader2, MessageSquare, Plus, Search, X } from "lucide-react";
 import { useCallback, useEffect, useRef, useState } from "react";
 import { createPortal } from "react-dom";
 import { toast } from "sonner";
@@ -169,6 +159,9 @@ export function MediaPane() {
 		? transcriptions[srcTranscriptAsset.id]
 		: undefined;
 
+	// "Import media" imports video OR audio (issue #350) — the picker returns which.
+	// An audio file becomes a kind:"audio" asset AND a timeline track in one action
+	// (importAudioAsset), the way a video becomes a clip.
 	const handleImport = async () => {
 		if (!projectId) {
 			toast.error(t("mediaStage.openProjectFirst"));
@@ -179,7 +172,8 @@ export function MediaPane() {
 		setBusy(true);
 		try {
 			const label = picker.name || basename(picker.path);
-			await addAsset(picker.path, label);
+			if (picker.kind === "audio") await importAudioAsset(picker.path, label);
+			else await addAsset(picker.path, label);
 			toast.success(t("mediaStage.added", { label }));
 		} catch (err) {
 			toast.error(t("mediaStage.couldNotAddAsset"), {
@@ -190,30 +184,6 @@ export function MediaPane() {
 		}
 	};
 
-	// Import an external audio file (voiceover / BGM / SFX) — issue #350. Adds the
-	// asset AND places a track at the playhead in one action (importAudioAsset), so
-	// the file lands visibly on the timeline the way importing a video lands a clip.
-	const handleImportAudio = async () => {
-		if (!projectId) {
-			toast.error(t("mediaStage.openProjectFirst"));
-			return;
-		}
-		const picker = await window.electronAPI?.openAudioFilePicker();
-		if (!picker?.success || !picker.path) return;
-		setBusy(true);
-		try {
-			const label = picker.name || basename(picker.path);
-			await importAudioAsset(picker.path, label);
-			toast.success(t("mediaStage.added", { label }));
-		} catch (err) {
-			toast.error(t("mediaStage.couldNotAddAudio"), {
-				description: err instanceof Error ? err.message : String(err),
-			});
-		} finally {
-			setBusy(false);
-		}
-	};
-
 	const filtered = (document?.assets ?? []).filter((a) => {
 		if (!query) return true;
 		const text = `${a.label} ${a.originalPath}`.toLowerCase();
@@ -286,15 +256,6 @@ export function MediaPane() {
 				<Plus size={14} />
 				{t("mediaStage.importMedia")}
 			</button>
-			<button
-				type="button"
-				className={styles.importBtn}
-				onClick={handleImportAudio}
-				disabled={!projectId || busy}
-			>
-				<Music size={14} />
-				{t("mediaStage.importAudio")}
-			</button>
 			{document?.transcript ? (
 				<div
 					style={{
diff --git a/src/components/ai-edition/v4/MediaStage.tsx b/src/components/ai-edition/v4/MediaStage.tsx
index 81fd07ed8..17f9e3f60 100644
--- a/src/components/ai-edition/v4/MediaStage.tsx
+++ b/src/components/ai-edition/v4/MediaStage.tsx
@@ -57,6 +57,7 @@ export function MediaStage({
 	const projectId = useProjectStore((s) => s.projectId);
 	const document = useProjectStore((s) => s.document);
 	const addAsset = useProjectStore((s) => s.addAsset);
+	const importAudioAsset = useProjectStore((s) => s.importAudioAsset);
 	// Transcripts are produced in the background as soon as a media lands here
 	// (see transcriptionStore) — this stage only reports where each one is at,
 	// and lets the user force a re-run in another language.
@@ -102,7 +103,10 @@ export function MediaStage({
 		setBusy(true);
 		try {
 			const label = picker.name || basename(picker.path);
-			await addAsset(picker.path, label);
+			// Audio imports become a kind:"audio" asset + a timeline track (issue #350);
+			// video imports become a clip. The picker says which was chosen.
+			if (picker.kind === "audio") await importAudioAsset(picker.path, label);
+			else await addAsset(picker.path, label);
 			toast.success(t("mediaStage.added", { label }));
 		} catch (err) {
 			toast.error(t("mediaStage.couldNotAddAsset"), {
diff --git a/src/i18n/locales/ar/dialogs.json b/src/i18n/locales/ar/dialogs.json
index 1032d22cb..6bf9bc569 100644
--- a/src/i18n/locales/ar/dialogs.json
+++ b/src/i18n/locales/ar/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "حفظ GIF المصدر",
 		"saveVideo": "حفظ الفيديو المصدر",
 		"selectVideo": "حدد ملف فيديو",
-		"selectAudio": "Select Audio File",
 		"saveProject": "حفظ مشروع OpenScreen",
 		"openProject": "فتح مشروع OpenScreen",
 		"gifImage": "صورة GIF",
 		"mp4Video": "فيديو MP4",
 		"videoFiles": "ملفات فيديو",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "مشروع OpenScreen",
 		"allFiles": "جميع الملفات"
 	}
diff --git a/src/i18n/locales/ar/editor.json b/src/i18n/locales/ar/editor.json
index f7e11c9f2..3bfe76664 100644
--- a/src/i18n/locales/ar/editor.json
+++ b/src/i18n/locales/ar/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "اللغة المكتشفة: {{language}}",
 		"noAudioTrack": "لا يوجد مسار صوتي",
 		"noAudioTrackHint": "لا يحتوي هذا الملف على مسار صوتي — لا يوجد ما يمكن نسخه.",
-		"noSpeechDetected": "لم يتم اكتشاف كلام",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "لم يتم اكتشاف كلام"
 	},
 	"exportDialog": {
 		"title": "تصدير",
diff --git a/src/i18n/locales/en/dialogs.json b/src/i18n/locales/en/dialogs.json
index 3d898d1a2..2dccd1cac 100644
--- a/src/i18n/locales/en/dialogs.json
+++ b/src/i18n/locales/en/dialogs.json
@@ -42,7 +42,6 @@
 		"step1Title": "1. Add Trim",
 		"step1DescriptionBefore": "Press ",
 		"step1DescriptionAfter": " or click the scissors icon to mark a section for removal.",
-
 		"step2Title": "2. Adjust",
 		"step2Description": "Drag the edges of the red region to cover exactly what you want to cut out."
 	},
@@ -80,13 +79,13 @@
 		"saveGif": "Save Exported GIF",
 		"saveVideo": "Save Exported Video",
 		"selectVideo": "Select Video File",
-		"selectAudio": "Select Audio File",
 		"saveProject": "Save OpenScreen Project",
 		"openProject": "Open OpenScreen Project",
 		"gifImage": "GIF Image",
 		"mp4Video": "MP4 Video",
 		"videoFiles": "Video Files",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen Project",
 		"allFiles": "All Files"
 	}
diff --git a/src/i18n/locales/en/editor.json b/src/i18n/locales/en/editor.json
index 8f4290399..4c3dd14c3 100644
--- a/src/i18n/locales/en/editor.json
+++ b/src/i18n/locales/en/editor.json
@@ -128,12 +128,10 @@
 	"mediaStage": {
 		"openProjectFirst": "Open a project first",
 		"couldNotAddAsset": "Could not add asset",
-		"couldNotAddAudio": "Could not add audio",
 		"searchPlaceholder": "Search media…",
 		"dragHint": "Drag a clip onto the timeline below to add it",
 		"emptyHint": "No media yet — import a recording to get started.",
 		"importMedia": "Import media",
-		"importAudio": "Import audio",
 		"added": "Added {{label}}",
 		"addToTimeline": "Add to timeline",
 		"addedToTimeline": "Added {{label}} to the timeline",
diff --git a/src/i18n/locales/es/dialogs.json b/src/i18n/locales/es/dialogs.json
index 10ebb2315..b2ec280f4 100644
--- a/src/i18n/locales/es/dialogs.json
+++ b/src/i18n/locales/es/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Guardar GIF exportado",
 		"saveVideo": "Guardar video exportado",
 		"selectVideo": "Seleccionar archivo de video",
-		"selectAudio": "Select Audio File",
 		"saveProject": "Guardar proyecto OpenScreen",
 		"openProject": "Abrir proyecto OpenScreen",
 		"gifImage": "Imagen GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "Archivos de video",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "Proyecto OpenScreen",
 		"allFiles": "Todos los archivos"
 	}
diff --git a/src/i18n/locales/es/editor.json b/src/i18n/locales/es/editor.json
index d67e97931..e2ef21429 100644
--- a/src/i18n/locales/es/editor.json
+++ b/src/i18n/locales/es/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "Idioma detectado: {{language}}",
 		"noAudioTrack": "Sin pista de audio",
 		"noAudioTrackHint": "Este medio no tiene pista de audio: no hay nada que transcribir.",
-		"noSpeechDetected": "No se detectó voz",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "No se detectó voz"
 	},
 	"exportDialog": {
 		"title": "Exportar",
diff --git a/src/i18n/locales/fr/dialogs.json b/src/i18n/locales/fr/dialogs.json
index a7691550e..bd1d02251 100644
--- a/src/i18n/locales/fr/dialogs.json
+++ b/src/i18n/locales/fr/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Enregistrer le GIF exporté",
 		"saveVideo": "Enregistrer la vidéo exportée",
 		"selectVideo": "Sélectionner un fichier vidéo",
-		"selectAudio": "Select Audio File",
 		"saveProject": "Enregistrer le projet OpenScreen",
 		"openProject": "Ouvrir un projet OpenScreen",
 		"gifImage": "Image GIF",
 		"mp4Video": "Vidéo MP4",
 		"videoFiles": "Fichiers vidéo",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "Projet OpenScreen",
 		"allFiles": "Tous les fichiers"
 	}
diff --git a/src/i18n/locales/fr/editor.json b/src/i18n/locales/fr/editor.json
index 4122a6e53..61694c0d2 100644
--- a/src/i18n/locales/fr/editor.json
+++ b/src/i18n/locales/fr/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "Langue détectée : {{language}}",
 		"noAudioTrack": "Aucune piste audio",
 		"noAudioTrackHint": "Ce média n'a pas de piste audio — il n'y a rien à transcrire.",
-		"noSpeechDetected": "Aucune parole détectée",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "Aucune parole détectée"
 	},
 	"exportDialog": {
 		"title": "Exporter",
diff --git a/src/i18n/locales/it/dialogs.json b/src/i18n/locales/it/dialogs.json
index b26a83da9..a40a61d9c 100644
--- a/src/i18n/locales/it/dialogs.json
+++ b/src/i18n/locales/it/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Salva GIF esportata",
 		"saveVideo": "Salva video esportato",
 		"selectVideo": "Seleziona file video",
-		"selectAudio": "Select Audio File",
 		"saveProject": "Salva progetto OpenScreen",
 		"openProject": "Apri progetto OpenScreen",
 		"gifImage": "Immagine GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "File video",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "Progetto OpenScreen",
 		"allFiles": "Tutti i file"
 	}
diff --git a/src/i18n/locales/it/editor.json b/src/i18n/locales/it/editor.json
index c4a529329..81603e049 100644
--- a/src/i18n/locales/it/editor.json
+++ b/src/i18n/locales/it/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "Lingua rilevata: {{language}}",
 		"noAudioTrack": "Nessuna traccia audio",
 		"noAudioTrackHint": "Questo contenuto non ha una traccia audio: non c'è nulla da trascrivere.",
-		"noSpeechDetected": "Nessun parlato rilevato",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "Nessun parlato rilevato"
 	},
 	"exportDialog": {
 		"title": "Esporta",
diff --git a/src/i18n/locales/ja-JP/dialogs.json b/src/i18n/locales/ja-JP/dialogs.json
index 911c2ad94..82637172b 100644
--- a/src/i18n/locales/ja-JP/dialogs.json
+++ b/src/i18n/locales/ja-JP/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "エクスポートしたGIFを保存",
 		"saveVideo": "エクスポートした動画を保存",
 		"selectVideo": "動画ファイルを選択",
-		"selectAudio": "Select Audio File",
 		"saveProject": "OpenScreen プロジェクトを保存",
 		"openProject": "OpenScreen プロジェクトを開く",
 		"gifImage": "GIF 画像",
 		"mp4Video": "MP4 動画",
 		"videoFiles": "動画ファイル",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen プロジェクト",
 		"allFiles": "すべてのファイル"
 	}
diff --git a/src/i18n/locales/ja-JP/editor.json b/src/i18n/locales/ja-JP/editor.json
index 399445997..d053b2fb3 100644
--- a/src/i18n/locales/ja-JP/editor.json
+++ b/src/i18n/locales/ja-JP/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "検出された言語: {{language}}",
 		"noAudioTrack": "音声トラックがありません",
 		"noAudioTrackHint": "このメディアには音声トラックがないため、文字起こしできません。",
-		"noSpeechDetected": "音声が検出されませんでした",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "音声が検出されませんでした"
 	},
 	"exportDialog": {
 		"title": "エクスポート",
diff --git a/src/i18n/locales/ko-KR/dialogs.json b/src/i18n/locales/ko-KR/dialogs.json
index d654a5f52..6930b9baf 100644
--- a/src/i18n/locales/ko-KR/dialogs.json
+++ b/src/i18n/locales/ko-KR/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "내보낸 GIF 저장",
 		"saveVideo": "내보낸 비디오 저장",
 		"selectVideo": "비디오 파일 선택",
-		"selectAudio": "Select Audio File",
 		"saveProject": "OpenScreen 프로젝트 저장",
 		"openProject": "OpenScreen 프로젝트 열기",
 		"gifImage": "GIF 이미지",
 		"mp4Video": "MP4 비디오",
 		"videoFiles": "비디오 파일",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen 프로젝트",
 		"allFiles": "모든 파일"
 	}
diff --git a/src/i18n/locales/ko-KR/editor.json b/src/i18n/locales/ko-KR/editor.json
index 61cb44708..c45d8d74b 100644
--- a/src/i18n/locales/ko-KR/editor.json
+++ b/src/i18n/locales/ko-KR/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "감지된 언어: {{language}}",
 		"noAudioTrack": "오디오 트랙 없음",
 		"noAudioTrackHint": "이 미디어에는 오디오 트랙이 없어 받아쓸 내용이 없습니다.",
-		"noSpeechDetected": "음성이 감지되지 않음",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "음성이 감지되지 않음"
 	},
 	"exportDialog": {
 		"title": "내보내기",
diff --git a/src/i18n/locales/pt-BR/dialogs.json b/src/i18n/locales/pt-BR/dialogs.json
index 7dbb4c642..c8cbeecaa 100644
--- a/src/i18n/locales/pt-BR/dialogs.json
+++ b/src/i18n/locales/pt-BR/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Salvar GIF Exportado",
 		"saveVideo": "Salvar Vídeo Exportado",
 		"selectVideo": "Selecionar Arquivo de Vídeo",
-		"selectAudio": "Select Audio File",
 		"saveProject": "Salvar Projeto OpenScreen",
 		"openProject": "Abrir Projeto OpenScreen",
 		"gifImage": "Imagem GIF",
 		"mp4Video": "Vídeo MP4",
 		"videoFiles": "Arquivos de Vídeo",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "Projeto OpenScreen",
 		"allFiles": "Todos os Arquivos"
 	}
diff --git a/src/i18n/locales/pt-BR/editor.json b/src/i18n/locales/pt-BR/editor.json
index b2ef15daf..5551edf96 100644
--- a/src/i18n/locales/pt-BR/editor.json
+++ b/src/i18n/locales/pt-BR/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "Idioma detectado: {{language}}",
 		"noAudioTrack": "Sem faixa de áudio",
 		"noAudioTrackHint": "Esta mídia não tem faixa de áudio — não há nada para transcrever.",
-		"noSpeechDetected": "Nenhuma fala detectada",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "Nenhuma fala detectada"
 	},
 	"exportDialog": {
 		"title": "Exportar",
diff --git a/src/i18n/locales/ru/dialogs.json b/src/i18n/locales/ru/dialogs.json
index 7e1dbaeed..e6154234a 100644
--- a/src/i18n/locales/ru/dialogs.json
+++ b/src/i18n/locales/ru/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Сохранить экспортированный GIF",
 		"saveVideo": "Сохранить экспортированное видео",
 		"selectVideo": "Выбрать видеофайл",
-		"selectAudio": "Select Audio File",
 		"saveProject": "Сохранить проект OpenScreen",
 		"openProject": "Открыть проект OpenScreen",
 		"gifImage": "GIF изображение",
 		"mp4Video": "MP4 видео",
 		"videoFiles": "Видеофайлы",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "Проект OpenScreen",
 		"allFiles": "Все файлы"
 	}
diff --git a/src/i18n/locales/ru/editor.json b/src/i18n/locales/ru/editor.json
index b7fe27ddb..e6eeae171 100644
--- a/src/i18n/locales/ru/editor.json
+++ b/src/i18n/locales/ru/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "Обнаруженный язык: {{language}}",
 		"noAudioTrack": "Нет аудиодорожки",
 		"noAudioTrackHint": "В этом медиафайле нет аудиодорожки — расшифровывать нечего.",
-		"noSpeechDetected": "Речь не обнаружена",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "Речь не обнаружена"
 	},
 	"exportDialog": {
 		"title": "Экспорт",
diff --git a/src/i18n/locales/tr/dialogs.json b/src/i18n/locales/tr/dialogs.json
index c6299d520..587e670e5 100644
--- a/src/i18n/locales/tr/dialogs.json
+++ b/src/i18n/locales/tr/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Dışa Aktarılan GIF'i Kaydet",
 		"saveVideo": "Dışa Aktarılan Videoyu Kaydet",
 		"selectVideo": "Video Dosyası Seç",
-		"selectAudio": "Select Audio File",
 		"saveProject": "OpenScreen Projesini Kaydet",
 		"openProject": "OpenScreen Projesini Aç",
 		"gifImage": "GIF Görüntüsü",
 		"mp4Video": "MP4 Video",
 		"videoFiles": "Video Dosyaları",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen Projesi",
 		"allFiles": "Tüm Dosyalar"
 	}
diff --git a/src/i18n/locales/tr/editor.json b/src/i18n/locales/tr/editor.json
index 0e9f2717a..555fc7de0 100644
--- a/src/i18n/locales/tr/editor.json
+++ b/src/i18n/locales/tr/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "Algılanan dil: {{language}}",
 		"noAudioTrack": "Ses parçası yok",
 		"noAudioTrackHint": "Bu medyada ses parçası yok — metne dökülecek bir şey bulunmuyor.",
-		"noSpeechDetected": "Konuşma algılanmadı",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "Konuşma algılanmadı"
 	},
 	"exportDialog": {
 		"title": "Dışa Aktar",
diff --git a/src/i18n/locales/vi/dialogs.json b/src/i18n/locales/vi/dialogs.json
index 213240763..55524a832 100644
--- a/src/i18n/locales/vi/dialogs.json
+++ b/src/i18n/locales/vi/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Lưu GIF đã xuất",
 		"saveVideo": "Lưu Video đã xuất",
 		"selectVideo": "Chọn tệp video",
-		"selectAudio": "Select Audio File",
 		"saveProject": "Lưu dự án OpenScreen",
 		"openProject": "Mở dự án OpenScreen",
 		"gifImage": "Hình ảnh GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "Tệp Video",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "Dự án OpenScreen",
 		"allFiles": "Tất cả các tệp"
 	}
diff --git a/src/i18n/locales/vi/editor.json b/src/i18n/locales/vi/editor.json
index 2dbb8b379..17db6ec4b 100644
--- a/src/i18n/locales/vi/editor.json
+++ b/src/i18n/locales/vi/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "Ngôn ngữ phát hiện: {{language}}",
 		"noAudioTrack": "Không có bản âm thanh",
 		"noAudioTrackHint": "Media này không có bản âm thanh — không có gì để phiên âm.",
-		"noSpeechDetected": "Không phát hiện giọng nói",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "Không phát hiện giọng nói"
 	},
 	"exportDialog": {
 		"title": "Xuất",
diff --git a/src/i18n/locales/zh-CN/dialogs.json b/src/i18n/locales/zh-CN/dialogs.json
index b28304f6c..efba46518 100644
--- a/src/i18n/locales/zh-CN/dialogs.json
+++ b/src/i18n/locales/zh-CN/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "保存导出的 GIF",
 		"saveVideo": "保存导出的视频",
 		"selectVideo": "选择视频文件",
-		"selectAudio": "Select Audio File",
 		"saveProject": "保存 OpenScreen 项目",
 		"openProject": "打开 OpenScreen 项目",
 		"gifImage": "GIF 图片",
 		"mp4Video": "MP4 视频",
 		"videoFiles": "视频文件",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen 项目",
 		"allFiles": "所有文件"
 	}
diff --git a/src/i18n/locales/zh-CN/editor.json b/src/i18n/locales/zh-CN/editor.json
index 907578e79..de7e52b55 100644
--- a/src/i18n/locales/zh-CN/editor.json
+++ b/src/i18n/locales/zh-CN/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "检测到的语言：{{language}}",
 		"noAudioTrack": "无音频轨道",
 		"noAudioTrackHint": "此媒体没有音频轨道，没有可转录的内容。",
-		"noSpeechDetected": "未检测到语音",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "未检测到语音"
 	},
 	"exportDialog": {
 		"title": "导出",
diff --git a/src/i18n/locales/zh-TW/dialogs.json b/src/i18n/locales/zh-TW/dialogs.json
index 6c3601511..527e87efa 100644
--- a/src/i18n/locales/zh-TW/dialogs.json
+++ b/src/i18n/locales/zh-TW/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "儲存匯出的 GIF",
 		"saveVideo": "儲存匯出的影片",
 		"selectVideo": "選擇影片檔案",
-		"selectAudio": "Select Audio File",
 		"saveProject": "儲存 OpenScreen 專案",
 		"openProject": "開啟 OpenScreen 專案",
 		"gifImage": "GIF 圖片",
 		"mp4Video": "MP4 影片",
 		"videoFiles": "影片檔案",
 		"audioFiles": "Audio Files",
+		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen 專案",
 		"allFiles": "所有檔案"
 	}
diff --git a/src/i18n/locales/zh-TW/editor.json b/src/i18n/locales/zh-TW/editor.json
index 2dab16c5b..f567810a5 100644
--- a/src/i18n/locales/zh-TW/editor.json
+++ b/src/i18n/locales/zh-TW/editor.json
@@ -160,9 +160,7 @@
 		"detectedLanguage": "偵測到的語言：{{language}}",
 		"noAudioTrack": "無音訊軌道",
 		"noAudioTrackHint": "此媒體沒有音訊軌道，沒有可轉錄的內容。",
-		"noSpeechDetected": "未偵測到語音",
-		"couldNotAddAudio": "Could not add audio",
-		"importAudio": "Import audio"
+		"noSpeechDetected": "未偵測到語音"
 	},
 	"exportDialog": {
 		"title": "匯出",

From a6ca70bc6cf74e21ad011325fe96db9c21a2942c Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 11:05:56 +0200
Subject: [PATCH 09/20] fix(editor): smooth audio-track preview and stop audio
 becoming a clip
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Two issues from testing the #350 import:

- Jitter: the preview re-seeked each imported track whenever it drifted
  >25 ms from the playhead. The primary/supplemental audio can use that
  tight leash because it syncs to the <video>'s own authoritative clock; an
  imported track syncs to virtualTimeSec, which is DERIVED from that clock
  each frame and slightly noisy, so at 25 ms it re-seeked most frames and
  each seek briefly stalled the element — the jitter. Widen the leash to
  300 ms while the element is playing (it free-runs in sync from the right
  offset; the wide leash only catches real scrubs / trim jumps), keeping the
  25 ms leash for the paused/seek case. Music beds don't need frame-tight
  sync — that's the video's job.

- Audio shown "along the recording": handleDropAsset (the media stage's
  "Add to timeline" button and drag) ran insertClipAt for ANY asset, so
  adding an imported audio asset built a video-style clip in the clip row on
  top of its lane track. An audio asset has no video and must never become a
  clip: route it to addAudioTrack instead, and reuse its existing track so
  the same file can't stack duplicate lanes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 src/components/ai-edition/NewEditorShell.tsx | 11 ++++++++++-
 src/components/ai-edition/VirtualPreview.tsx | 12 +++++++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/components/ai-edition/NewEditorShell.tsx b/src/components/ai-edition/NewEditorShell.tsx
index 746271aab..2810bdaa3 100644
--- a/src/components/ai-edition/NewEditorShell.tsx
+++ b/src/components/ai-edition/NewEditorShell.tsx
@@ -427,7 +427,16 @@ export function NewEditorShell() {
 	const handleDropAsset = useCallback(
 		(assetId: string) =>
 			enqueueTimelineWrite(() => {
-				const at = useProjectStore.getState().document?.timeline.clips.length ?? 0;
+				const doc = useProjectStore.getState().document;
+				// An audio asset has no video, so it must never become a clip (issue
+				// #350) — it goes on the audio lane as a track. Adding it "to the
+				// timeline" reuses its existing track if it already has one (importing
+				// already placed one) so the same file can't stack up duplicate lanes.
+				if (doc?.assets.find((a) => a.id === assetId)?.kind === "audio") {
+					if (doc.audioTracks.some((t) => t.assetId === assetId)) return Promise.resolve();
+					return tl.addAudioTrack(assetId).then(() => undefined);
+				}
+				const at = doc?.timeline.clips.length ?? 0;
 				return tl.insertClipAt(assetId, at);
 			}).catch((error) => {
 				toast.error(te("mediaStage.couldNotAddAsset"), {
diff --git a/src/components/ai-edition/VirtualPreview.tsx b/src/components/ai-edition/VirtualPreview.tsx
index b0d6d0685..eb9e83943 100644
--- a/src/components/ai-edition/VirtualPreview.tsx
+++ b/src/components/ai-edition/VirtualPreview.tsx
@@ -533,7 +533,17 @@ export function VirtualPreview({
 				const trackTarget = resolveTimelineAudioPlayback(virtualTimeSecRef.current, track);
 				if (el.playbackRate !== v.playbackRate) el.playbackRate = v.playbackRate;
 				el.volume = Math.min(1, audioGainScalar(track.gainDb) * globalGain);
-				if (Math.abs(el.currentTime - trackTarget.targetTimeSec) > 0.025) {
+				// Only re-seek on a real discontinuity (a scrub, a trim jump, a first
+				// play), NOT on the sub-frame drift of normal playback. The primary audio
+				// can afford a 25 ms leash because it syncs to the <video>'s own
+				// authoritative clock; an imported track syncs to `virtualTimeSec`, which is
+				// DERIVED from that clock each frame and so is slightly noisy — at a 25 ms
+				// leash it re-seeks most frames, and each seek briefly stalls the element:
+				// the jitter. A started element already plays at the right rate from the
+				// right offset, so it free-runs in sync; this wide leash just catches the
+				// jumps. BGM/voiceover tolerates it; frame-tight sync is the video's job.
+				const leashSec = !el.paused && trackTarget.shouldPlay ? 0.3 : 0.025;
+				if (Math.abs(el.currentTime - trackTarget.targetTimeSec) > leashSec) {
 					try {
 						el.currentTime = trackTarget.targetTimeSec;
 					} catch {

From 7b167ae47d701fdd0300f9a9fbea845e8ea268b3 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 11:25:33 +0200
Subject: [PATCH 10/20] feat(editor): add audio from the timeline toolbar, not
 the media tab
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Reworks the #350 import UX per testing feedback: the media tab arranges
video CLIPS (it chains them), which is the wrong model for an audio overlay.
Audio is now added the way an annotation is — a timeline action.

- New "Add audio" tool in the timeline toolbar (music icon, next to
  zoom/speed/camera): opens an audio-only picker and places a track at the
  playhead via importAudioAsset.
- The media tab is video-only again: open-video-file-picker reverts to video
  extensions, restored the dedicated open-audio-file-picker for the toolbar,
  and MediaStage / MediaPane / EditorEmptyState import video only.
- Audio assets are hidden from the media lists (MediaStage + MediaPane) —
  they're managed on the timeline lane (select the pill to edit/remove), so
  they never appear as chainable clips.
- i18n: audioTrack.add / importFailed, restored selectAudio, dropped the
  now-unused mediaFiles, across all 13 locales.

The handleDropAsset guard (audio → track, never a clip) stays as a backstop.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 electron/electron-env.d.ts                    | 11 ++-
 electron/ipc/handlers.ts                      | 86 +++++++++++--------
 electron/preload.ts                           |  3 +
 .../ai-edition/EditorEmptyState.tsx           | 10 +--
 src/components/ai-edition/LeftPanel.tsx       | 11 ++-
 src/components/ai-edition/v4/MediaStage.tsx   | 11 ++-
 src/components/ai-edition/v4/V4Timeline.tsx   | 28 ++++++
 src/i18n/locales/ar/dialogs.json              |  2 +-
 src/i18n/locales/ar/settings.json             |  2 +
 src/i18n/locales/en/dialogs.json              |  2 +-
 src/i18n/locales/en/settings.json             |  2 +
 src/i18n/locales/es/dialogs.json              |  2 +-
 src/i18n/locales/es/settings.json             |  2 +
 src/i18n/locales/fr/dialogs.json              |  2 +-
 src/i18n/locales/fr/settings.json             |  2 +
 src/i18n/locales/it/dialogs.json              |  2 +-
 src/i18n/locales/it/settings.json             |  2 +
 src/i18n/locales/ja-JP/dialogs.json           |  2 +-
 src/i18n/locales/ja-JP/settings.json          |  2 +
 src/i18n/locales/ko-KR/dialogs.json           |  2 +-
 src/i18n/locales/ko-KR/settings.json          |  2 +
 src/i18n/locales/pt-BR/dialogs.json           |  2 +-
 src/i18n/locales/pt-BR/settings.json          |  2 +
 src/i18n/locales/ru/dialogs.json              |  2 +-
 src/i18n/locales/ru/settings.json             |  2 +
 src/i18n/locales/tr/dialogs.json              |  2 +-
 src/i18n/locales/tr/settings.json             |  2 +
 src/i18n/locales/vi/dialogs.json              |  2 +-
 src/i18n/locales/vi/settings.json             |  2 +
 src/i18n/locales/zh-CN/dialogs.json           |  2 +-
 src/i18n/locales/zh-CN/settings.json          |  2 +
 src/i18n/locales/zh-TW/dialogs.json           |  2 +-
 src/i18n/locales/zh-TW/settings.json          |  2 +
 33 files changed, 143 insertions(+), 69 deletions(-)

diff --git a/electron/electron-env.d.ts b/electron/electron-env.d.ts
index 8bd505bb9..ea33e78ec 100644
--- a/electron/electron-env.d.ts
+++ b/electron/electron-env.d.ts
@@ -278,17 +278,22 @@ interface Window {
 			message?: string;
 			error?: string;
 		}>;
-		// "Import media" — video or audio (issue #350). `kind` says which was picked
-		// so the caller routes an audio file to an audio asset+track.
 		openVideoFilePicker: () => Promise<{
 			success: boolean;
 			path?: string;
-			kind?: "video" | "audio";
 			// Browser-mode shim only: a blob: URL has no meaningful basename, so
 			// the shim carries the picked File's real name here for the label.
 			name?: string;
 			canceled?: boolean;
 		}>;
+		// Import an external audio file from the timeline toolbar (issue #350).
+		openAudioFilePicker: () => Promise<{
+			success: boolean;
+			path?: string;
+			name?: string;
+			canceled?: boolean;
+			message?: string;
+		}>;
 		setCurrentVideoPath: (path: string) => Promise<{ success: boolean }>;
 		setCurrentRecordingSession: (
 			session: import("../src/lib/recordingSession").RecordingSession | null,
diff --git a/electron/ipc/handlers.ts b/electron/ipc/handlers.ts
index d0d43b27a..b9b7d23f6 100644
--- a/electron/ipc/handlers.ts
+++ b/electron/ipc/handlers.ts
@@ -3610,10 +3610,8 @@ export function registerIpcHandlers(
 		}
 	});
 
-	// "Import media" (issue #350): one picker for video AND audio. It offers both
-	// extension sets and approves whichever the pick is, returning `kind` so the
-	// renderer routes an audio file to an audio asset+track and a video file to a
-	// clip. Keeps its historical name so every existing caller keeps working.
+	// The media tab imports VIDEO (it arranges clips). Audio is imported from the
+	// timeline toolbar instead (issue #350) — see `open-audio-file-picker` below.
 	ipcMain.handle("open-video-file-picker", async () => {
 		try {
 			const dialogOptions = buildDialogOptions(
@@ -3621,31 +3619,56 @@ export function registerIpcHandlers(
 					title: mainT("dialogs", "fileDialogs.selectVideo"),
 					defaultPath: RECORDINGS_DIR,
 					filters: [
-						{
-							name: mainT("dialogs", "fileDialogs.mediaFiles"),
-							extensions: [
-								"webm",
-								"mp4",
-								"mov",
-								"avi",
-								"mkv",
-								"m4v",
-								"wmv",
-								"flv",
-								"ts",
-								"mp3",
-								"wav",
-								"m4a",
-								"aac",
-								"flac",
-								"ogg",
-								"opus",
-							],
-						},
 						{
 							name: mainT("dialogs", "fileDialogs.videoFiles"),
 							extensions: ["webm", "mp4", "mov", "avi", "mkv", "m4v", "wmv", "flv", "ts"],
 						},
+						{ name: mainT("dialogs", "fileDialogs.allFiles"), extensions: ["*"] },
+					],
+					properties: ["openFile"],
+				},
+				getMainWindow(),
+			);
+			const result = await dialog.showOpenDialog(dialogOptions);
+
+			if (result.canceled || result.filePaths.length === 0) {
+				return { success: false, canceled: true };
+			}
+
+			const normalizedPath = await approveReadableVideoPath(result.filePaths[0]);
+			if (!normalizedPath) {
+				return {
+					success: false,
+					message: "Selected file is not a supported readable video file",
+				};
+			}
+
+			currentProjectPath = null;
+			return {
+				success: true,
+				path: normalizedPath,
+			};
+		} catch (error) {
+			console.error("Failed to open file picker:", error);
+			return {
+				success: false,
+				message: "Failed to open file picker",
+				error: String(error),
+			};
+		}
+	});
+
+	// Import an external audio file (voiceover / BGM / SFX) — issue #350. Driven by
+	// the timeline's "Add audio" tool: audio is a timeline overlay (like an
+	// annotation), not a media-tab clip, so it has its own audio-only picker and the
+	// renderer adds it as a kind:"audio" asset + track at the playhead.
+	ipcMain.handle("open-audio-file-picker", async () => {
+		try {
+			const dialogOptions = buildDialogOptions(
+				{
+					title: mainT("dialogs", "fileDialogs.selectAudio"),
+					defaultPath: RECORDINGS_DIR,
+					filters: [
 						{
 							name: mainT("dialogs", "fileDialogs.audioFiles"),
 							extensions: ["mp3", "wav", "m4a", "aac", "flac", "ogg", "opus"],
@@ -3662,28 +3685,23 @@ export function registerIpcHandlers(
 				return { success: false, canceled: true };
 			}
 
-			// Try video first, then audio — the extension gate is the only difference,
-			// and the two sets don't overlap, so at most one approves.
-			const videoPath = await approveReadableVideoPath(result.filePaths[0]);
-			const normalizedPath = videoPath ?? (await approveReadableAudioPath(result.filePaths[0]));
+			const normalizedPath = await approveReadableAudioPath(result.filePaths[0]);
 			if (!normalizedPath) {
 				return {
 					success: false,
-					message: "Selected file is not a supported readable media file",
+					message: "Selected file is not a supported readable audio file",
 				};
 			}
 
-			currentProjectPath = null;
 			return {
 				success: true,
 				path: normalizedPath,
-				kind: videoPath ? ("video" as const) : ("audio" as const),
 			};
 		} catch (error) {
-			console.error("Failed to open file picker:", error);
+			console.error("Failed to open audio file picker:", error);
 			return {
 				success: false,
-				message: "Failed to open file picker",
+				message: "Failed to open audio file picker",
 				error: String(error),
 			};
 		}
diff --git a/electron/preload.ts b/electron/preload.ts
index 6aff16407..16227f110 100644
--- a/electron/preload.ts
+++ b/electron/preload.ts
@@ -276,6 +276,9 @@ contextBridge.exposeInMainWorld("electronAPI", {
 	openVideoFilePicker: () => {
 		return ipcRenderer.invoke("open-video-file-picker");
 	},
+	openAudioFilePicker: () => {
+		return ipcRenderer.invoke("open-audio-file-picker");
+	},
 	setCurrentVideoPath: (path: string) => {
 		return ipcRenderer.invoke("set-current-video-path", path);
 	},
diff --git a/src/components/ai-edition/EditorEmptyState.tsx b/src/components/ai-edition/EditorEmptyState.tsx
index 6daec79be..226171dca 100644
--- a/src/components/ai-edition/EditorEmptyState.tsx
+++ b/src/components/ai-edition/EditorEmptyState.tsx
@@ -47,7 +47,6 @@ export function EditorEmptyState({
 
 	const createProject = useProjectStore((s) => s.createProject);
 	const addAsset = useProjectStore((s) => s.addAsset);
-	const importAudioAsset = useProjectStore((s) => s.importAudioAsset);
 	const loadProject = useProjectStore((s) => s.loadProject);
 
 	const ensureProject = useCallback(async (): Promise<string | null> => {
@@ -64,17 +63,14 @@ export function EditorEmptyState({
 			const projectId = await ensureProject();
 			if (!projectId) return;
 			const label = result.name || result.path.split(/[\\/]/).pop() || "Recording";
-			// The picker imports media (issue #350): audio lands as a kind:"audio"
-			// asset + track, video as a clip.
-			if (result.kind === "audio") await importAudioAsset(result.path, label);
-			else await addAsset(result.path, label);
+			await addAsset(result.path, label);
 		} catch (err) {
 			setDropError("load-failed");
 			// ponytail: surface as a console message only — the dialog above
 			// already tells the user something went wrong.
-			console.error("Failed to import media", err);
+			console.error("Failed to import video", err);
 		}
-	}, [addAsset, importAudioAsset, ensureProject]);
+	}, [addAsset, ensureProject]);
 
 	// A loaded project JSON is either a current AxcutDocument (has its own
 	// `schemaVersion`) or a legacy EditorProjectData that must be migrated.
diff --git a/src/components/ai-edition/LeftPanel.tsx b/src/components/ai-edition/LeftPanel.tsx
index 3b0836d87..00ab408ce 100644
--- a/src/components/ai-edition/LeftPanel.tsx
+++ b/src/components/ai-edition/LeftPanel.tsx
@@ -147,7 +147,6 @@ export function MediaPane() {
 	const projectId = useProjectStore((s) => s.projectId);
 	const document = useProjectStore((s) => s.document);
 	const addAsset = useProjectStore((s) => s.addAsset);
-	const importAudioAsset = useProjectStore((s) => s.importAudioAsset);
 	// Transcripts land on their own (transcriptionStore's background pass); the
 	// pane reports where each one is at and offers a per-asset re-run.
 	const transcriptions = useAssetTranscriptions();
@@ -159,9 +158,6 @@ export function MediaPane() {
 		? transcriptions[srcTranscriptAsset.id]
 		: undefined;
 
-	// "Import media" imports video OR audio (issue #350) — the picker returns which.
-	// An audio file becomes a kind:"audio" asset AND a timeline track in one action
-	// (importAudioAsset), the way a video becomes a clip.
 	const handleImport = async () => {
 		if (!projectId) {
 			toast.error(t("mediaStage.openProjectFirst"));
@@ -172,8 +168,7 @@ export function MediaPane() {
 		setBusy(true);
 		try {
 			const label = picker.name || basename(picker.path);
-			if (picker.kind === "audio") await importAudioAsset(picker.path, label);
-			else await addAsset(picker.path, label);
+			await addAsset(picker.path, label);
 			toast.success(t("mediaStage.added", { label }));
 		} catch (err) {
 			toast.error(t("mediaStage.couldNotAddAsset"), {
@@ -184,7 +179,11 @@ export function MediaPane() {
 		}
 	};
 
+	// Only video assets are listed here — the media panel arranges clips. Imported
+	// audio (issue #350) lives on the timeline's audio lane, added from the timeline
+	// toolbar, and is managed there (select its pill to edit / remove).
 	const filtered = (document?.assets ?? []).filter((a) => {
+		if (a.kind === "audio") return false;
 		if (!query) return true;
 		const text = `${a.label} ${a.originalPath}`.toLowerCase();
 		return text.includes(query.toLowerCase());
diff --git a/src/components/ai-edition/v4/MediaStage.tsx b/src/components/ai-edition/v4/MediaStage.tsx
index 17f9e3f60..6b1b74b92 100644
--- a/src/components/ai-edition/v4/MediaStage.tsx
+++ b/src/components/ai-edition/v4/MediaStage.tsx
@@ -57,7 +57,6 @@ export function MediaStage({
 	const projectId = useProjectStore((s) => s.projectId);
 	const document = useProjectStore((s) => s.document);
 	const addAsset = useProjectStore((s) => s.addAsset);
-	const importAudioAsset = useProjectStore((s) => s.importAudioAsset);
 	// Transcripts are produced in the background as soon as a media lands here
 	// (see transcriptionStore) — this stage only reports where each one is at,
 	// and lets the user force a re-run in another language.
@@ -74,7 +73,10 @@ export function MediaStage({
 		[locale, t],
 	);
 
-	const assets = document?.assets ?? [];
+	// Video only — this stage arranges clips. Imported audio (issue #350) is a
+	// timeline overlay added from the timeline toolbar, not a clip, so it never
+	// appears in this list.
+	const assets = (document?.assets ?? []).filter((a) => a.kind !== "audio");
 	const filtered = useMemo(
 		() =>
 			assets.filter((a) => {
@@ -103,10 +105,7 @@ export function MediaStage({
 		setBusy(true);
 		try {
 			const label = picker.name || basename(picker.path);
-			// Audio imports become a kind:"audio" asset + a timeline track (issue #350);
-			// video imports become a clip. The picker says which was chosen.
-			if (picker.kind === "audio") await importAudioAsset(picker.path, label);
-			else await addAsset(picker.path, label);
+			await addAsset(picker.path, label);
 			toast.success(t("mediaStage.added", { label }));
 		} catch (err) {
 			toast.error(t("mediaStage.couldNotAddAsset"), {
diff --git a/src/components/ai-edition/v4/V4Timeline.tsx b/src/components/ai-edition/v4/V4Timeline.tsx
index 9bb1279ed..fd14d7ce3 100644
--- a/src/components/ai-edition/v4/V4Timeline.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.tsx
@@ -485,6 +485,24 @@ export function V4Timeline({
 		shiftPx: number;
 	} | null>(null);
 	const { settings, set: setSettings } = useEditorSettings();
+	const importAudioAsset = useProjectStore((s) => s.importAudioAsset);
+
+	// Import an audio file straight onto the timeline (issue #350). Audio is a
+	// timeline overlay like an annotation, not a media-tab clip, so it is added
+	// from here: pick a file, then `importAudioAsset` adds a kind:"audio" asset and
+	// places a track at the playhead in one step.
+	const handleAddAudio = useCallback(async () => {
+		const picker = await window.electronAPI?.openAudioFilePicker?.();
+		if (!picker?.success || !picker.path) return;
+		try {
+			const label = picker.name || picker.path.split(/[\\/]/).pop() || "Audio";
+			await importAudioAsset(picker.path, label);
+		} catch (err) {
+			toast.error(ts("audioTrack.importFailed"), {
+				description: err instanceof Error ? err.message : String(err),
+			});
+		}
+	}, [importAudioAsset, ts]);
 
 	const [autoEnhanceOpen, setAutoEnhanceOpen] = useState(false);
 	const [autoBusy, setAutoBusy] = useState(false);
@@ -1570,6 +1588,16 @@ export function V4Timeline({
 						>
 							<Maximize2 size={15} />
 						</button>
+						<span className={styles.tlToolSep} aria-hidden />
+						<button
+							type="button"
+							className={styles.tlToolBtn}
+							title={ts("audioTrack.add")}
+							aria-label={ts("audioTrack.add")}
+							onClick={() => void handleAddAudio()}
+						>
+							<Music size={15} />
+						</button>
 					</div>
 				) : (
 					// Media is an ARRANGING surface: add, remove, reorder. Nothing here
diff --git a/src/i18n/locales/ar/dialogs.json b/src/i18n/locales/ar/dialogs.json
index 6bf9bc569..1032d22cb 100644
--- a/src/i18n/locales/ar/dialogs.json
+++ b/src/i18n/locales/ar/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "حفظ GIF المصدر",
 		"saveVideo": "حفظ الفيديو المصدر",
 		"selectVideo": "حدد ملف فيديو",
+		"selectAudio": "Select Audio File",
 		"saveProject": "حفظ مشروع OpenScreen",
 		"openProject": "فتح مشروع OpenScreen",
 		"gifImage": "صورة GIF",
 		"mp4Video": "فيديو MP4",
 		"videoFiles": "ملفات فيديو",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "مشروع OpenScreen",
 		"allFiles": "جميع الملفات"
 	}
diff --git a/src/i18n/locales/ar/settings.json b/src/i18n/locales/ar/settings.json
index df9fc4e31..d15a9d7b3 100644
--- a/src/i18n/locales/ar/settings.json
+++ b/src/i18n/locales/ar/settings.json
@@ -321,6 +321,8 @@
 		"help": "اضبط مستوى إخراج الصوت. يُطبَّق بالطريقة نفسها في المعاينة وعند التصدير."
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/en/dialogs.json b/src/i18n/locales/en/dialogs.json
index 2dccd1cac..9ce8e3ded 100644
--- a/src/i18n/locales/en/dialogs.json
+++ b/src/i18n/locales/en/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Save Exported GIF",
 		"saveVideo": "Save Exported Video",
 		"selectVideo": "Select Video File",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Save OpenScreen Project",
 		"openProject": "Open OpenScreen Project",
 		"gifImage": "GIF Image",
 		"mp4Video": "MP4 Video",
 		"videoFiles": "Video Files",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen Project",
 		"allFiles": "All Files"
 	}
diff --git a/src/i18n/locales/en/settings.json b/src/i18n/locales/en/settings.json
index 09148229e..26d40d926 100644
--- a/src/i18n/locales/en/settings.json
+++ b/src/i18n/locales/en/settings.json
@@ -72,6 +72,8 @@
 		"reset": "Reset audio"
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/es/dialogs.json b/src/i18n/locales/es/dialogs.json
index b2ec280f4..10ebb2315 100644
--- a/src/i18n/locales/es/dialogs.json
+++ b/src/i18n/locales/es/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Guardar GIF exportado",
 		"saveVideo": "Guardar video exportado",
 		"selectVideo": "Seleccionar archivo de video",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Guardar proyecto OpenScreen",
 		"openProject": "Abrir proyecto OpenScreen",
 		"gifImage": "Imagen GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "Archivos de video",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "Proyecto OpenScreen",
 		"allFiles": "Todos los archivos"
 	}
diff --git a/src/i18n/locales/es/settings.json b/src/i18n/locales/es/settings.json
index 73678ae96..2d928cb17 100644
--- a/src/i18n/locales/es/settings.json
+++ b/src/i18n/locales/es/settings.json
@@ -321,6 +321,8 @@
 		"help": "Ajusta el nivel de salida del audio. Se aplica igual en la vista previa y en la exportación."
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/fr/dialogs.json b/src/i18n/locales/fr/dialogs.json
index bd1d02251..a7691550e 100644
--- a/src/i18n/locales/fr/dialogs.json
+++ b/src/i18n/locales/fr/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Enregistrer le GIF exporté",
 		"saveVideo": "Enregistrer la vidéo exportée",
 		"selectVideo": "Sélectionner un fichier vidéo",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Enregistrer le projet OpenScreen",
 		"openProject": "Ouvrir un projet OpenScreen",
 		"gifImage": "Image GIF",
 		"mp4Video": "Vidéo MP4",
 		"videoFiles": "Fichiers vidéo",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "Projet OpenScreen",
 		"allFiles": "Tous les fichiers"
 	}
diff --git a/src/i18n/locales/fr/settings.json b/src/i18n/locales/fr/settings.json
index 4c9f961d3..f85619019 100644
--- a/src/i18n/locales/fr/settings.json
+++ b/src/i18n/locales/fr/settings.json
@@ -321,6 +321,8 @@
 		"help": "Ajustez le niveau de sortie audio. Il s’applique à l’identique dans l’aperçu et à l’export."
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/it/dialogs.json b/src/i18n/locales/it/dialogs.json
index a40a61d9c..b26a83da9 100644
--- a/src/i18n/locales/it/dialogs.json
+++ b/src/i18n/locales/it/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Salva GIF esportata",
 		"saveVideo": "Salva video esportato",
 		"selectVideo": "Seleziona file video",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Salva progetto OpenScreen",
 		"openProject": "Apri progetto OpenScreen",
 		"gifImage": "Immagine GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "File video",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "Progetto OpenScreen",
 		"allFiles": "Tutti i file"
 	}
diff --git a/src/i18n/locales/it/settings.json b/src/i18n/locales/it/settings.json
index 2c23b41a1..ebf420fc4 100644
--- a/src/i18n/locales/it/settings.json
+++ b/src/i18n/locales/it/settings.json
@@ -321,6 +321,8 @@
 		"help": "Regola il livello di uscita audio. Si applica allo stesso modo nell’anteprima e nell’esportazione."
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/ja-JP/dialogs.json b/src/i18n/locales/ja-JP/dialogs.json
index 82637172b..911c2ad94 100644
--- a/src/i18n/locales/ja-JP/dialogs.json
+++ b/src/i18n/locales/ja-JP/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "エクスポートしたGIFを保存",
 		"saveVideo": "エクスポートした動画を保存",
 		"selectVideo": "動画ファイルを選択",
+		"selectAudio": "Select Audio File",
 		"saveProject": "OpenScreen プロジェクトを保存",
 		"openProject": "OpenScreen プロジェクトを開く",
 		"gifImage": "GIF 画像",
 		"mp4Video": "MP4 動画",
 		"videoFiles": "動画ファイル",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen プロジェクト",
 		"allFiles": "すべてのファイル"
 	}
diff --git a/src/i18n/locales/ja-JP/settings.json b/src/i18n/locales/ja-JP/settings.json
index bf9dfc721..f93966fe7 100644
--- a/src/i18n/locales/ja-JP/settings.json
+++ b/src/i18n/locales/ja-JP/settings.json
@@ -321,6 +321,8 @@
 		"help": "音声の出力レベルを調整します。プレビューと書き出しで同じように適用されます。"
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/ko-KR/dialogs.json b/src/i18n/locales/ko-KR/dialogs.json
index 6930b9baf..d654a5f52 100644
--- a/src/i18n/locales/ko-KR/dialogs.json
+++ b/src/i18n/locales/ko-KR/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "내보낸 GIF 저장",
 		"saveVideo": "내보낸 비디오 저장",
 		"selectVideo": "비디오 파일 선택",
+		"selectAudio": "Select Audio File",
 		"saveProject": "OpenScreen 프로젝트 저장",
 		"openProject": "OpenScreen 프로젝트 열기",
 		"gifImage": "GIF 이미지",
 		"mp4Video": "MP4 비디오",
 		"videoFiles": "비디오 파일",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen 프로젝트",
 		"allFiles": "모든 파일"
 	}
diff --git a/src/i18n/locales/ko-KR/settings.json b/src/i18n/locales/ko-KR/settings.json
index e9acc2b34..38177fbe6 100644
--- a/src/i18n/locales/ko-KR/settings.json
+++ b/src/i18n/locales/ko-KR/settings.json
@@ -321,6 +321,8 @@
 		"help": "오디오 출력 레벨을 조정합니다. 미리보기와 내보내기에 동일하게 적용됩니다."
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/pt-BR/dialogs.json b/src/i18n/locales/pt-BR/dialogs.json
index c8cbeecaa..7dbb4c642 100644
--- a/src/i18n/locales/pt-BR/dialogs.json
+++ b/src/i18n/locales/pt-BR/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Salvar GIF Exportado",
 		"saveVideo": "Salvar Vídeo Exportado",
 		"selectVideo": "Selecionar Arquivo de Vídeo",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Salvar Projeto OpenScreen",
 		"openProject": "Abrir Projeto OpenScreen",
 		"gifImage": "Imagem GIF",
 		"mp4Video": "Vídeo MP4",
 		"videoFiles": "Arquivos de Vídeo",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "Projeto OpenScreen",
 		"allFiles": "Todos os Arquivos"
 	}
diff --git a/src/i18n/locales/pt-BR/settings.json b/src/i18n/locales/pt-BR/settings.json
index 929aa96c3..284754e67 100644
--- a/src/i18n/locales/pt-BR/settings.json
+++ b/src/i18n/locales/pt-BR/settings.json
@@ -321,6 +321,8 @@
 		"help": "Ajuste o nível de saída do áudio. Ele se aplica da mesma forma na prévia e na exportação."
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/ru/dialogs.json b/src/i18n/locales/ru/dialogs.json
index e6154234a..7e1dbaeed 100644
--- a/src/i18n/locales/ru/dialogs.json
+++ b/src/i18n/locales/ru/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Сохранить экспортированный GIF",
 		"saveVideo": "Сохранить экспортированное видео",
 		"selectVideo": "Выбрать видеофайл",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Сохранить проект OpenScreen",
 		"openProject": "Открыть проект OpenScreen",
 		"gifImage": "GIF изображение",
 		"mp4Video": "MP4 видео",
 		"videoFiles": "Видеофайлы",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "Проект OpenScreen",
 		"allFiles": "Все файлы"
 	}
diff --git a/src/i18n/locales/ru/settings.json b/src/i18n/locales/ru/settings.json
index 0d2bbe7e3..7b5fe714b 100644
--- a/src/i18n/locales/ru/settings.json
+++ b/src/i18n/locales/ru/settings.json
@@ -321,6 +321,8 @@
 		"help": "Настройте уровень звука на выходе. Он одинаково применяется в предпросмотре и при экспорте."
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/tr/dialogs.json b/src/i18n/locales/tr/dialogs.json
index 587e670e5..c6299d520 100644
--- a/src/i18n/locales/tr/dialogs.json
+++ b/src/i18n/locales/tr/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Dışa Aktarılan GIF'i Kaydet",
 		"saveVideo": "Dışa Aktarılan Videoyu Kaydet",
 		"selectVideo": "Video Dosyası Seç",
+		"selectAudio": "Select Audio File",
 		"saveProject": "OpenScreen Projesini Kaydet",
 		"openProject": "OpenScreen Projesini Aç",
 		"gifImage": "GIF Görüntüsü",
 		"mp4Video": "MP4 Video",
 		"videoFiles": "Video Dosyaları",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen Projesi",
 		"allFiles": "Tüm Dosyalar"
 	}
diff --git a/src/i18n/locales/tr/settings.json b/src/i18n/locales/tr/settings.json
index 7512f7092..b4ff7e2e9 100644
--- a/src/i18n/locales/tr/settings.json
+++ b/src/i18n/locales/tr/settings.json
@@ -321,6 +321,8 @@
 		"help": "Ses çıkış seviyesini ayarlayın. Önizlemede ve dışa aktarmada aynı şekilde uygulanır."
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/vi/dialogs.json b/src/i18n/locales/vi/dialogs.json
index 55524a832..213240763 100644
--- a/src/i18n/locales/vi/dialogs.json
+++ b/src/i18n/locales/vi/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Lưu GIF đã xuất",
 		"saveVideo": "Lưu Video đã xuất",
 		"selectVideo": "Chọn tệp video",
+		"selectAudio": "Select Audio File",
 		"saveProject": "Lưu dự án OpenScreen",
 		"openProject": "Mở dự án OpenScreen",
 		"gifImage": "Hình ảnh GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "Tệp Video",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "Dự án OpenScreen",
 		"allFiles": "Tất cả các tệp"
 	}
diff --git a/src/i18n/locales/vi/settings.json b/src/i18n/locales/vi/settings.json
index 3b1d64926..5eac703dc 100644
--- a/src/i18n/locales/vi/settings.json
+++ b/src/i18n/locales/vi/settings.json
@@ -321,6 +321,8 @@
 		"help": "Điều chỉnh mức đầu ra của âm thanh. Nó được áp dụng giống hệt nhau trong bản xem trước và khi xuất."
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/zh-CN/dialogs.json b/src/i18n/locales/zh-CN/dialogs.json
index efba46518..b28304f6c 100644
--- a/src/i18n/locales/zh-CN/dialogs.json
+++ b/src/i18n/locales/zh-CN/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "保存导出的 GIF",
 		"saveVideo": "保存导出的视频",
 		"selectVideo": "选择视频文件",
+		"selectAudio": "Select Audio File",
 		"saveProject": "保存 OpenScreen 项目",
 		"openProject": "打开 OpenScreen 项目",
 		"gifImage": "GIF 图片",
 		"mp4Video": "MP4 视频",
 		"videoFiles": "视频文件",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen 项目",
 		"allFiles": "所有文件"
 	}
diff --git a/src/i18n/locales/zh-CN/settings.json b/src/i18n/locales/zh-CN/settings.json
index cf4d66a9d..a6dc6705d 100644
--- a/src/i18n/locales/zh-CN/settings.json
+++ b/src/i18n/locales/zh-CN/settings.json
@@ -321,6 +321,8 @@
 		"help": "调整音频输出电平。它在预览和导出中的效果完全一致。"
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
diff --git a/src/i18n/locales/zh-TW/dialogs.json b/src/i18n/locales/zh-TW/dialogs.json
index 527e87efa..6c3601511 100644
--- a/src/i18n/locales/zh-TW/dialogs.json
+++ b/src/i18n/locales/zh-TW/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "儲存匯出的 GIF",
 		"saveVideo": "儲存匯出的影片",
 		"selectVideo": "選擇影片檔案",
+		"selectAudio": "Select Audio File",
 		"saveProject": "儲存 OpenScreen 專案",
 		"openProject": "開啟 OpenScreen 專案",
 		"gifImage": "GIF 圖片",
 		"mp4Video": "MP4 影片",
 		"videoFiles": "影片檔案",
 		"audioFiles": "Audio Files",
-		"mediaFiles": "Media Files",
 		"openscreenProject": "OpenScreen 專案",
 		"allFiles": "所有檔案"
 	}
diff --git a/src/i18n/locales/zh-TW/settings.json b/src/i18n/locales/zh-TW/settings.json
index e20fe1081..8fd8d340d 100644
--- a/src/i18n/locales/zh-TW/settings.json
+++ b/src/i18n/locales/zh-TW/settings.json
@@ -322,6 +322,8 @@
 		"help": "調整音訊輸出電平。它在預覽與匯出中的效果完全一致。"
 	},
 	"audioTrack": {
+		"add": "Add audio track",
+		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",

From 5dd510d1921d4681c9524dd04383e045bd1ec9a9 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 11:42:25 +0200
Subject: [PATCH 11/20] refine(editor): tidy the audio toolbar button and
 inspector pane

Testing feedback on the #350 audio UI:

- Move the "Add audio" toolbar button left of the first divider (grouped with
  auto-enhance, ahead of the region tools) instead of isolated at the end.
- AudioTrackPane: header is now the generic "Audio track"; the file name
  moves into the body. Drop the mute button and the start-offset field
  (position and mute are handled on the lane), leaving volume + delete. The
  delete button now matches the region panes' danger-outlined style.
- Remove the now-unused audioTrack.offset / mute / unmute strings across all
  13 locales and correct the help text.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 src/components/ai-edition/RightPanes.tsx    | 98 ++++++++-------------
 src/components/ai-edition/v4/V4Timeline.tsx | 19 ++--
 src/i18n/locales/ar/settings.json           |  3 -
 src/i18n/locales/en/settings.json           |  5 +-
 src/i18n/locales/es/settings.json           |  3 -
 src/i18n/locales/fr/settings.json           |  3 -
 src/i18n/locales/it/settings.json           |  3 -
 src/i18n/locales/ja-JP/settings.json        |  3 -
 src/i18n/locales/ko-KR/settings.json        |  3 -
 src/i18n/locales/pt-BR/settings.json        |  3 -
 src/i18n/locales/ru/settings.json           |  3 -
 src/i18n/locales/tr/settings.json           |  3 -
 src/i18n/locales/vi/settings.json           |  3 -
 src/i18n/locales/zh-CN/settings.json        |  3 -
 src/i18n/locales/zh-TW/settings.json        |  3 -
 15 files changed, 49 insertions(+), 109 deletions(-)

diff --git a/src/components/ai-edition/RightPanes.tsx b/src/components/ai-edition/RightPanes.tsx
index d6f8e3711..4bbb057f7 100644
--- a/src/components/ai-edition/RightPanes.tsx
+++ b/src/components/ai-edition/RightPanes.tsx
@@ -16,8 +16,6 @@ import {
 	Music,
 	Sliders,
 	Trash2,
-	Volume2,
-	VolumeX,
 } from "lucide-react";
 import {
 	type ChangeEvent,
@@ -2109,9 +2107,10 @@ type TimelineApi = ReturnType<typeof useTimeline>;
 
 // Per-track controls for the selected imported audio track (issue #350). Shown by
 // the inspector in place of the facet when an audio track is selected (see
-// FloatingInspector). Volume drives a local live value during the drag and only
-// writes (one undo step) on release, the same shape as the global output-gain
-// slider; mute / offset / remove each write once.
+// FloatingInspector). The header is the generic "Audio track"; the body leads
+// with the file name, then the volume (a local live value during the drag,
+// committed as one undo step on release), then a delete button styled like the
+// region panes' (position and mute are edited on the lane itself).
 export function AudioTrackPane({ tl }: { tl: TimelineApi }) {
 	const ts = useScopedT("settings");
 	const trackId = tl.selectedAudioTrackId;
@@ -2119,20 +2118,44 @@ export function AudioTrackPane({ tl }: { tl: TimelineApi }) {
 	const asset = track ? tl.assets.find((a) => a.id === track.assetId) : undefined;
 	// Live-drag value for the volume slider; null means "show the committed gain".
 	const [liveGain, setLiveGain] = useState<number | null>(null);
-	// Draft text for the offset field; null means "show the track's real offset".
-	const [offsetDraft, setOffsetDraft] = useState<string | null>(null);
 	if (!track) return null;
-	const label = track.label || asset?.label || ts("audioTrack.defaultLabel");
-
-	const commitOffset = () => {
-		if (offsetDraft === null) return;
-		const parsed = Number.parseFloat(offsetDraft);
-		if (Number.isFinite(parsed)) void tl.moveAudioTrack(track.id, Math.max(0, parsed));
-		setOffsetDraft(null);
+	const fileName = track.label || asset?.label || asset?.originalPath?.split(/[\\/]/).pop() || "";
+
+	// Match the region panes' danger-outlined delete button (see SelectionPane).
+	const deleteBtnStyle: CSSProperties = {
+		display: "inline-flex",
+		alignItems: "center",
+		justifyContent: "center",
+		gap: 7,
+		padding: "9px 14px",
+		borderRadius: 10,
+		border: "1px solid var(--danger)",
+		background: "var(--danger-soft)",
+		color: "var(--danger)",
+		font: "600 13px var(--font-display)",
+		cursor: "pointer",
 	};
 
 	return (
-		<Pane title={label} icon={<Music size={14} />} helpText={ts("audioTrack.help")}>
+		<Pane
+			title={ts("audioTrack.defaultLabel")}
+			icon={<Music size={14} />}
+			helpText={ts("audioTrack.help")}
+		>
+			<div
+				title={fileName}
+				style={{
+					fontSize: 13,
+					fontWeight: 600,
+					color: "var(--fg)",
+					overflow: "hidden",
+					textOverflow: "ellipsis",
+					whiteSpace: "nowrap",
+					margin: "0 0 10px",
+				}}
+			>
+				{fileName}
+			</div>
 			<div className={styles.sliderGrid}>
 				<SliderCell
 					label={ts("audioTrack.volume")}
@@ -2142,7 +2165,6 @@ export function AudioTrackPane({ tl }: { tl: TimelineApi }) {
 					step={0.5}
 					decimals={1}
 					suffix=" dB"
-					disabled={track.mute}
 					onChange={(value) => setLiveGain(value)}
 					onCommit={() => {
 						if (liveGain !== null) void tl.setAudioTrackGain(track.id, liveGain);
@@ -2150,52 +2172,10 @@ export function AudioTrackPane({ tl }: { tl: TimelineApi }) {
 					}}
 				/>
 			</div>
-			<label
-				style={{
-					display: "flex",
-					alignItems: "center",
-					justifyContent: "space-between",
-					gap: 8,
-					fontSize: 12,
-					color: "var(--meta)",
-					margin: "2px 0 8px",
-				}}
-			>
-				<span>{ts("audioTrack.offset")}</span>
-				<input
-					type="number"
-					min={0}
-					step={0.1}
-					value={offsetDraft ?? track.timelineStartSec.toFixed(2)}
-					onChange={(e) => setOffsetDraft(e.target.value)}
-					onBlur={commitOffset}
-					onKeyDown={(e) => {
-						if (e.key === "Enter") e.currentTarget.blur();
-					}}
-					style={{
-						width: 84,
-						padding: "4px 6px",
-						background: "var(--surface-warm)",
-						border: "1px solid var(--border-soft)",
-						borderRadius: "var(--r-sm)",
-						color: "var(--fg)",
-						font: "12px var(--font-body)",
-						textAlign: "right",
-					}}
-				/>
-			</label>
 			<button
 				type="button"
-				className={styles.secondaryBtn}
-				onClick={() => void tl.toggleAudioTrackMute(track.id)}
-			>
-				{track.mute ? <VolumeX size={14} /> : <Volume2 size={14} />}
-				{track.mute ? ts("audioTrack.unmute") : ts("audioTrack.mute")}
-			</button>
-			<button
-				type="button"
-				className={styles.secondaryBtn}
 				onClick={() => void tl.removeAudioTrack(track.id)}
+				style={deleteBtnStyle}
 			>
 				<Trash2 size={14} />
 				{ts("audioTrack.remove")}
diff --git a/src/components/ai-edition/v4/V4Timeline.tsx b/src/components/ai-edition/v4/V4Timeline.tsx
index fd14d7ce3..b945c7dcf 100644
--- a/src/components/ai-edition/v4/V4Timeline.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.tsx
@@ -1534,6 +1534,15 @@ export function V4Timeline({
 								</div>
 							</PopoverContent>
 						</Popover>
+						<button
+							type="button"
+							className={styles.tlToolBtn}
+							title={ts("audioTrack.add")}
+							aria-label={ts("audioTrack.add")}
+							onClick={() => void handleAddAudio()}
+						>
+							<Music size={15} />
+						</button>
 						<span className={styles.tlToolSep} aria-hidden />
 						{tools.map((tool) => (
 							<button
@@ -1588,16 +1597,6 @@ export function V4Timeline({
 						>
 							<Maximize2 size={15} />
 						</button>
-						<span className={styles.tlToolSep} aria-hidden />
-						<button
-							type="button"
-							className={styles.tlToolBtn}
-							title={ts("audioTrack.add")}
-							aria-label={ts("audioTrack.add")}
-							onClick={() => void handleAddAudio()}
-						>
-							<Music size={15} />
-						</button>
 					</div>
 				) : (
 					// Media is an ARRANGING surface: add, remove, reorder. Nothing here
diff --git a/src/i18n/locales/ar/settings.json b/src/i18n/locales/ar/settings.json
index d15a9d7b3..9597cab92 100644
--- a/src/i18n/locales/ar/settings.json
+++ b/src/i18n/locales/ar/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/en/settings.json b/src/i18n/locales/en/settings.json
index 26d40d926..97f9b55e2 100644
--- a/src/i18n/locales/en/settings.json
+++ b/src/i18n/locales/en/settings.json
@@ -75,11 +75,8 @@
 		"add": "Add audio track",
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
+		"help": "Volume for this imported audio track. It mixes over the recording in the preview and the export. Drag the track on the timeline to move or trim it.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	},
 	"effects": {
diff --git a/src/i18n/locales/es/settings.json b/src/i18n/locales/es/settings.json
index 2d928cb17..d8f72c5d4 100644
--- a/src/i18n/locales/es/settings.json
+++ b/src/i18n/locales/es/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/fr/settings.json b/src/i18n/locales/fr/settings.json
index f85619019..e3cccda0a 100644
--- a/src/i18n/locales/fr/settings.json
+++ b/src/i18n/locales/fr/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/it/settings.json b/src/i18n/locales/it/settings.json
index ebf420fc4..97a566f3e 100644
--- a/src/i18n/locales/it/settings.json
+++ b/src/i18n/locales/it/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/ja-JP/settings.json b/src/i18n/locales/ja-JP/settings.json
index f93966fe7..9a7512236 100644
--- a/src/i18n/locales/ja-JP/settings.json
+++ b/src/i18n/locales/ja-JP/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/ko-KR/settings.json b/src/i18n/locales/ko-KR/settings.json
index 38177fbe6..b7f1f3661 100644
--- a/src/i18n/locales/ko-KR/settings.json
+++ b/src/i18n/locales/ko-KR/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/pt-BR/settings.json b/src/i18n/locales/pt-BR/settings.json
index 284754e67..d2268a3a3 100644
--- a/src/i18n/locales/pt-BR/settings.json
+++ b/src/i18n/locales/pt-BR/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/ru/settings.json b/src/i18n/locales/ru/settings.json
index 7b5fe714b..ecaf4cdfc 100644
--- a/src/i18n/locales/ru/settings.json
+++ b/src/i18n/locales/ru/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/tr/settings.json b/src/i18n/locales/tr/settings.json
index b4ff7e2e9..56feec071 100644
--- a/src/i18n/locales/tr/settings.json
+++ b/src/i18n/locales/tr/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/vi/settings.json b/src/i18n/locales/vi/settings.json
index 5eac703dc..795adf8ed 100644
--- a/src/i18n/locales/vi/settings.json
+++ b/src/i18n/locales/vi/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/zh-CN/settings.json b/src/i18n/locales/zh-CN/settings.json
index a6dc6705d..b93d1fdc3 100644
--- a/src/i18n/locales/zh-CN/settings.json
+++ b/src/i18n/locales/zh-CN/settings.json
@@ -326,9 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }
diff --git a/src/i18n/locales/zh-TW/settings.json b/src/i18n/locales/zh-TW/settings.json
index 8fd8d340d..dd5260841 100644
--- a/src/i18n/locales/zh-TW/settings.json
+++ b/src/i18n/locales/zh-TW/settings.json
@@ -327,9 +327,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"offset": "Start (s)",
-		"mute": "Mute",
-		"unmute": "Unmute",
 		"remove": "Remove track"
 	}
 }

From 84a439d4c64009bfb5cc84ac12b631b480a6346c Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 11:50:02 +0200
Subject: [PATCH 12/20] refine(editor): reposition Add audio and make Delete
 track span

More #350 UI feedback:

- Move the "Add audio" toolbar button to directly right of "Add annotation"
  (the comment tool), rendered inside the tool row via a Fragment.
- Rename the inspector's "Remove track" to "Delete track" and make the button
  full-width, matching the region panes' delete button.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 src/components/ai-edition/RightPanes.tsx    |  3 +-
 src/components/ai-edition/v4/V4Timeline.tsx | 57 +++++++++++----------
 src/i18n/locales/ar/settings.json           |  2 +-
 src/i18n/locales/en/settings.json           |  2 +-
 src/i18n/locales/es/settings.json           |  2 +-
 src/i18n/locales/fr/settings.json           |  2 +-
 src/i18n/locales/it/settings.json           |  2 +-
 src/i18n/locales/ja-JP/settings.json        |  2 +-
 src/i18n/locales/ko-KR/settings.json        |  2 +-
 src/i18n/locales/pt-BR/settings.json        |  2 +-
 src/i18n/locales/ru/settings.json           |  2 +-
 src/i18n/locales/tr/settings.json           |  2 +-
 src/i18n/locales/vi/settings.json           |  2 +-
 src/i18n/locales/zh-CN/settings.json        |  2 +-
 src/i18n/locales/zh-TW/settings.json        |  2 +-
 15 files changed, 46 insertions(+), 40 deletions(-)

diff --git a/src/components/ai-edition/RightPanes.tsx b/src/components/ai-edition/RightPanes.tsx
index 4bbb057f7..ef99b9e06 100644
--- a/src/components/ai-edition/RightPanes.tsx
+++ b/src/components/ai-edition/RightPanes.tsx
@@ -2123,7 +2123,8 @@ export function AudioTrackPane({ tl }: { tl: TimelineApi }) {
 
 	// Match the region panes' danger-outlined delete button (see SelectionPane).
 	const deleteBtnStyle: CSSProperties = {
-		display: "inline-flex",
+		display: "flex",
+		width: "100%",
 		alignItems: "center",
 		justifyContent: "center",
 		gap: 7,
diff --git a/src/components/ai-edition/v4/V4Timeline.tsx b/src/components/ai-edition/v4/V4Timeline.tsx
index b945c7dcf..9fcfbf48e 100644
--- a/src/components/ai-edition/v4/V4Timeline.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.tsx
@@ -15,6 +15,7 @@ import {
 	ZoomIn,
 } from "lucide-react";
 import {
+	Fragment,
 	memo,
 	type PointerEvent as ReactPointerEvent,
 	useCallback,
@@ -1534,34 +1535,38 @@ export function V4Timeline({
 								</div>
 							</PopoverContent>
 						</Popover>
-						<button
-							type="button"
-							className={styles.tlToolBtn}
-							title={ts("audioTrack.add")}
-							aria-label={ts("audioTrack.add")}
-							onClick={() => void handleAddAudio()}
-						>
-							<Music size={15} />
-						</button>
 						<span className={styles.tlToolSep} aria-hidden />
 						{tools.map((tool) => (
-							<button
-								type="button"
-								key={tool.id}
-								className={styles.tlToolBtn}
-								title={tool.label}
-								aria-label={tool.label}
-								onClick={() => {
-									// Read at CLICK time: a render-time value would be one zoom
-									// notch stale when the user zooms and immediately creates.
-									const dur = newRegionDurationSec();
-									if (tool.id === "speed") void tl.addSpeed(dur);
-									if (tool.id === "comment") void tl.addAnnotation(dur);
-									if (tool.id === "cut") void tl.addTrim(dur);
-								}}
-							>
-								{tool.icon}
-							</button>
+							<Fragment key={tool.id}>
+								<button
+									type="button"
+									className={styles.tlToolBtn}
+									title={tool.label}
+									aria-label={tool.label}
+									onClick={() => {
+										// Read at CLICK time: a render-time value would be one zoom
+										// notch stale when the user zooms and immediately creates.
+										const dur = newRegionDurationSec();
+										if (tool.id === "speed") void tl.addSpeed(dur);
+										if (tool.id === "comment") void tl.addAnnotation(dur);
+										if (tool.id === "cut") void tl.addTrim(dur);
+									}}
+								>
+									{tool.icon}
+								</button>
+								{/* Add audio sits right after Add annotation (issue #350). */}
+								{tool.id === "comment" ? (
+									<button
+										type="button"
+										className={styles.tlToolBtn}
+										title={ts("audioTrack.add")}
+										aria-label={ts("audioTrack.add")}
+										onClick={() => void handleAddAudio()}
+									>
+										<Music size={15} />
+									</button>
+								) : null}
+							</Fragment>
 						))}
 						<button
 							type="button"
diff --git a/src/i18n/locales/ar/settings.json b/src/i18n/locales/ar/settings.json
index 9597cab92..98a6e4b8e 100644
--- a/src/i18n/locales/ar/settings.json
+++ b/src/i18n/locales/ar/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/en/settings.json b/src/i18n/locales/en/settings.json
index 97f9b55e2..078513b17 100644
--- a/src/i18n/locales/en/settings.json
+++ b/src/i18n/locales/en/settings.json
@@ -77,7 +77,7 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume for this imported audio track. It mixes over the recording in the preview and the export. Drag the track on the timeline to move or trim it.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	},
 	"effects": {
 		"title": "Composition",
diff --git a/src/i18n/locales/es/settings.json b/src/i18n/locales/es/settings.json
index d8f72c5d4..f9d3c32b0 100644
--- a/src/i18n/locales/es/settings.json
+++ b/src/i18n/locales/es/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/fr/settings.json b/src/i18n/locales/fr/settings.json
index e3cccda0a..319a3ba1f 100644
--- a/src/i18n/locales/fr/settings.json
+++ b/src/i18n/locales/fr/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/it/settings.json b/src/i18n/locales/it/settings.json
index 97a566f3e..65996c0c9 100644
--- a/src/i18n/locales/it/settings.json
+++ b/src/i18n/locales/it/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/ja-JP/settings.json b/src/i18n/locales/ja-JP/settings.json
index 9a7512236..bcd6ec0c9 100644
--- a/src/i18n/locales/ja-JP/settings.json
+++ b/src/i18n/locales/ja-JP/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/ko-KR/settings.json b/src/i18n/locales/ko-KR/settings.json
index b7f1f3661..1e257d07d 100644
--- a/src/i18n/locales/ko-KR/settings.json
+++ b/src/i18n/locales/ko-KR/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/pt-BR/settings.json b/src/i18n/locales/pt-BR/settings.json
index d2268a3a3..6503237e1 100644
--- a/src/i18n/locales/pt-BR/settings.json
+++ b/src/i18n/locales/pt-BR/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/ru/settings.json b/src/i18n/locales/ru/settings.json
index ecaf4cdfc..d1ab01a21 100644
--- a/src/i18n/locales/ru/settings.json
+++ b/src/i18n/locales/ru/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/tr/settings.json b/src/i18n/locales/tr/settings.json
index 56feec071..2209a041f 100644
--- a/src/i18n/locales/tr/settings.json
+++ b/src/i18n/locales/tr/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/vi/settings.json b/src/i18n/locales/vi/settings.json
index 795adf8ed..ae8d9f0c8 100644
--- a/src/i18n/locales/vi/settings.json
+++ b/src/i18n/locales/vi/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/zh-CN/settings.json b/src/i18n/locales/zh-CN/settings.json
index b93d1fdc3..fe81c09b1 100644
--- a/src/i18n/locales/zh-CN/settings.json
+++ b/src/i18n/locales/zh-CN/settings.json
@@ -326,6 +326,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/zh-TW/settings.json b/src/i18n/locales/zh-TW/settings.json
index dd5260841..862f755f8 100644
--- a/src/i18n/locales/zh-TW/settings.json
+++ b/src/i18n/locales/zh-TW/settings.json
@@ -327,6 +327,6 @@
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
 		"volume": "Volume",
-		"remove": "Remove track"
+		"remove": "Delete track"
 	}
 }

From 86a78b9c729de42c0ddc9143f4d9fe954ee096ed Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 11:55:36 +0200
Subject: [PATCH 13/20] refine(editor): match the audio-track pane to the
 global Audio pane

Per #350 feedback: label the slider "Output level" (reusing audio.outputGain,
the same string the global Audio pane shows) and add a "Reset audio" button
that zeroes the track's gain, styled like the global pane's reset. Drop the
now-unused audioTrack.volume string.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 src/components/ai-edition/RightPanes.tsx | 12 +++++++++++-
 src/i18n/locales/ar/settings.json        |  1 -
 src/i18n/locales/en/settings.json        |  1 -
 src/i18n/locales/es/settings.json        |  1 -
 src/i18n/locales/fr/settings.json        |  1 -
 src/i18n/locales/it/settings.json        |  1 -
 src/i18n/locales/ja-JP/settings.json     |  1 -
 src/i18n/locales/ko-KR/settings.json     |  1 -
 src/i18n/locales/pt-BR/settings.json     |  1 -
 src/i18n/locales/ru/settings.json        |  1 -
 src/i18n/locales/tr/settings.json        |  1 -
 src/i18n/locales/vi/settings.json        |  1 -
 src/i18n/locales/zh-CN/settings.json     |  1 -
 src/i18n/locales/zh-TW/settings.json     |  1 -
 14 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/src/components/ai-edition/RightPanes.tsx b/src/components/ai-edition/RightPanes.tsx
index ef99b9e06..cb3ace165 100644
--- a/src/components/ai-edition/RightPanes.tsx
+++ b/src/components/ai-edition/RightPanes.tsx
@@ -2159,7 +2159,7 @@ export function AudioTrackPane({ tl }: { tl: TimelineApi }) {
 			</div>
 			<div className={styles.sliderGrid}>
 				<SliderCell
-					label={ts("audioTrack.volume")}
+					label={ts("audio.outputGain")}
 					value={liveGain ?? track.gainDb}
 					min={-AUDIO_GAIN_DB_LIMIT}
 					max={AUDIO_GAIN_DB_LIMIT}
@@ -2173,6 +2173,16 @@ export function AudioTrackPane({ tl }: { tl: TimelineApi }) {
 					}}
 				/>
 			</div>
+			<button
+				type="button"
+				className={styles.secondaryBtn}
+				onClick={() => {
+					setLiveGain(null);
+					void tl.setAudioTrackGain(track.id, 0);
+				}}
+			>
+				{ts("audio.reset")}
+			</button>
 			<button
 				type="button"
 				onClick={() => void tl.removeAudioTrack(track.id)}
diff --git a/src/i18n/locales/ar/settings.json b/src/i18n/locales/ar/settings.json
index 98a6e4b8e..38dd38a5c 100644
--- a/src/i18n/locales/ar/settings.json
+++ b/src/i18n/locales/ar/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/en/settings.json b/src/i18n/locales/en/settings.json
index 078513b17..2080b0317 100644
--- a/src/i18n/locales/en/settings.json
+++ b/src/i18n/locales/en/settings.json
@@ -76,7 +76,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume for this imported audio track. It mixes over the recording in the preview and the export. Drag the track on the timeline to move or trim it.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	},
 	"effects": {
diff --git a/src/i18n/locales/es/settings.json b/src/i18n/locales/es/settings.json
index f9d3c32b0..2464f3980 100644
--- a/src/i18n/locales/es/settings.json
+++ b/src/i18n/locales/es/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/fr/settings.json b/src/i18n/locales/fr/settings.json
index 319a3ba1f..f93a7bd8a 100644
--- a/src/i18n/locales/fr/settings.json
+++ b/src/i18n/locales/fr/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/it/settings.json b/src/i18n/locales/it/settings.json
index 65996c0c9..f6c9b32e7 100644
--- a/src/i18n/locales/it/settings.json
+++ b/src/i18n/locales/it/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/ja-JP/settings.json b/src/i18n/locales/ja-JP/settings.json
index bcd6ec0c9..91b194c4c 100644
--- a/src/i18n/locales/ja-JP/settings.json
+++ b/src/i18n/locales/ja-JP/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/ko-KR/settings.json b/src/i18n/locales/ko-KR/settings.json
index 1e257d07d..f0b381f8e 100644
--- a/src/i18n/locales/ko-KR/settings.json
+++ b/src/i18n/locales/ko-KR/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/pt-BR/settings.json b/src/i18n/locales/pt-BR/settings.json
index 6503237e1..cdfcc39d8 100644
--- a/src/i18n/locales/pt-BR/settings.json
+++ b/src/i18n/locales/pt-BR/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/ru/settings.json b/src/i18n/locales/ru/settings.json
index d1ab01a21..fa11b5061 100644
--- a/src/i18n/locales/ru/settings.json
+++ b/src/i18n/locales/ru/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/tr/settings.json b/src/i18n/locales/tr/settings.json
index 2209a041f..1444cb21a 100644
--- a/src/i18n/locales/tr/settings.json
+++ b/src/i18n/locales/tr/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/vi/settings.json b/src/i18n/locales/vi/settings.json
index ae8d9f0c8..e6191c8a2 100644
--- a/src/i18n/locales/vi/settings.json
+++ b/src/i18n/locales/vi/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/zh-CN/settings.json b/src/i18n/locales/zh-CN/settings.json
index fe81c09b1..30de68b90 100644
--- a/src/i18n/locales/zh-CN/settings.json
+++ b/src/i18n/locales/zh-CN/settings.json
@@ -325,7 +325,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }
diff --git a/src/i18n/locales/zh-TW/settings.json b/src/i18n/locales/zh-TW/settings.json
index 862f755f8..d3a17cb24 100644
--- a/src/i18n/locales/zh-TW/settings.json
+++ b/src/i18n/locales/zh-TW/settings.json
@@ -326,7 +326,6 @@
 		"importFailed": "Could not add audio",
 		"defaultLabel": "Audio track",
 		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"volume": "Volume",
 		"remove": "Delete track"
 	}
 }

From 0ef1af3430cf21b11d1d2d627d73935204e9fa59 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 12:14:44 +0200
Subject: [PATCH 14/20] refactor(editor): drop the superseded audio-track
 move/resize ops

moveAudioTrack and resizeAudioTrack lost their only callers when the
inspector's offset field was removed; the lane's edge-drag commits position
and trim together through placeAudioTrack (setAudioTrackPlacement), so the
separate position-only and trim-only ops were dead. Remove the two hook
wrappers, the two pure document ops (moveAudioTrack, setAudioTrackTrim),
their tests, and their document-write-audit rows. placeAudioTrack /
setAudioTrackPlacement stay and still cover both edges.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 .../ai-edition/document/audioTracks.test.ts   | 28 +-------------
 src/lib/ai-edition/document/audioTracks.ts    | 37 ++-----------------
 .../store/documentWriteAudit.test.ts          |  5 +--
 src/lib/ai-edition/store/useTimeline.test.ts  | 14 ++++---
 src/lib/ai-edition/store/useTimeline.ts       | 25 -------------
 5 files changed, 16 insertions(+), 93 deletions(-)

diff --git a/src/lib/ai-edition/document/audioTracks.test.ts b/src/lib/ai-edition/document/audioTracks.test.ts
index 2223c67be..cddee21dd 100644
--- a/src/lib/ai-edition/document/audioTracks.test.ts
+++ b/src/lib/ai-edition/document/audioTracks.test.ts
@@ -2,12 +2,10 @@ import { describe, expect, it } from "vitest";
 import { createAudioTrack, createEmptyDocument } from "../schema";
 import {
 	appendAudioTrack,
-	moveAudioTrack,
 	removeAudioTrack,
 	setAudioTrackGain,
 	setAudioTrackMute,
 	setAudioTrackPlacement,
-	setAudioTrackTrim,
 } from "./audioTracks";
 
 const emptyDoc = () => createEmptyDocument({ projectId: "p", title: "t" });
@@ -32,28 +30,6 @@ describe("audioTracks document ops (issue #350)", () => {
 		expect(removeAudioTrack(doc, "nope").audioTracks).toEqual([track]);
 	});
 
-	it("moveAudioTrack repositions the head and floors negatives at 0", () => {
-		const { doc, track } = docWithTrack();
-		expect(moveAudioTrack(doc, track.id, 9).audioTracks[0]?.timelineStartSec).toBe(9);
-		expect(moveAudioTrack(doc, track.id, -4).audioTracks[0]?.timelineStartSec).toBe(0);
-		expect(moveAudioTrack(doc, track.id, Number.NaN).audioTracks[0]?.timelineStartSec).toBe(0);
-	});
-
-	it("setAudioTrackTrim keeps trimEnd >= trimStart so the result stays schema-valid", () => {
-		const { doc, track } = docWithTrack();
-		const trimmed = setAudioTrackTrim(doc, track.id, { trimStartSec: 4, trimEndSec: 2 });
-		expect(trimmed.audioTracks[0]?.trimStartSec).toBe(4);
-		// trimEnd was pulled up to trimStart rather than left below it.
-		expect(trimmed.audioTracks[0]?.trimEndSec).toBe(4);
-	});
-
-	it("setAudioTrackTrim clears the tail trim when trimEndSec is undefined", () => {
-		const { doc, track } = docWithTrack();
-		const withTail = setAudioTrackTrim(doc, track.id, { trimStartSec: 1, trimEndSec: 10 });
-		const cleared = setAudioTrackTrim(withTail, track.id, { trimStartSec: 1 });
-		expect(cleared.audioTracks[0]?.trimEndSec).toBeUndefined();
-	});
-
 	it("setAudioTrackGain stores a finite dB and defaults NaN to 0", () => {
 		const { doc, track } = docWithTrack();
 		expect(setAudioTrackGain(doc, track.id, -6).audioTracks[0]?.gainDb).toBe(-6);
@@ -97,8 +73,8 @@ describe("audioTracks document ops (issue #350)", () => {
 		const a = createAudioTrack({ assetId: "asset_1", durationSec: 10 });
 		const b = createAudioTrack({ assetId: "asset_2", durationSec: 20 });
 		const doc = appendAudioTrack(appendAudioTrack(emptyDoc(), a), b);
-		const next = moveAudioTrack(doc, b.id, 7);
+		const next = setAudioTrackGain(doc, b.id, -6);
 		expect(next.audioTracks[0]).toEqual(a);
-		expect(next.audioTracks[1]?.timelineStartSec).toBe(7);
+		expect(next.audioTracks[1]?.gainDb).toBe(-6);
 	});
 });
diff --git a/src/lib/ai-edition/document/audioTracks.ts b/src/lib/ai-edition/document/audioTracks.ts
index a35704fcf..5fb49c55b 100644
--- a/src/lib/ai-edition/document/audioTracks.ts
+++ b/src/lib/ai-edition/document/audioTracks.ts
@@ -37,42 +37,13 @@ function updateAudioTrack(
 	};
 }
 
-/** Reposition a track's head on the programme (output-timeline seconds). */
-export function moveAudioTrack(
-	doc: AxcutDocument,
-	trackId: string,
-	timelineStartSec: number,
-): AxcutDocument {
-	return updateAudioTrack(doc, trackId, (t) => ({
-		...t,
-		timelineStartSec: finiteNonNeg(timelineStartSec),
-	}));
-}
-
-/**
- * Window the source file. `trimStartSec` floors at 0; `trimEndSec`, when given,
- * is pulled up to at least `trimStartSec` so the result always satisfies the
- * schema's `trimEndSec >= trimStartSec` rule. Pass `trimEndSec: undefined` to
- * clear the tail trim (play to the end of the file).
- */
-export function setAudioTrackTrim(
-	doc: AxcutDocument,
-	trackId: string,
-	trim: { trimStartSec: number; trimEndSec?: number },
-): AxcutDocument {
-	const trimStartSec = finiteNonNeg(trim.trimStartSec);
-	const trimEndSec =
-		trim.trimEndSec === undefined
-			? undefined
-			: Math.max(trimStartSec, finiteNonNeg(trim.trimEndSec));
-	return updateAudioTrack(doc, trackId, (t) => ({ ...t, trimStartSec, trimEndSec }));
-}
-
 /**
  * Set position and trim together in one write — what an edge-drag on the lane
  * needs: dragging the left edge moves both `timelineStartSec` and `trimStartSec`
- * at once, and committing that as two ops would be two undo steps. Same guards as
- * {@link moveAudioTrack} and {@link setAudioTrackTrim} so the result stays valid.
+ * at once, and committing that as two ops would be two undo steps. Floors both at
+ * 0 and pulls `trimEndSec` up to at least `trimStartSec` so the result always
+ * satisfies the schema's `trimEndSec >= trimStartSec` rule; `trimEndSec:
+ * undefined` clears the tail trim (play to the end of the file).
  */
 export function setAudioTrackPlacement(
 	doc: AxcutDocument,
diff --git a/src/lib/ai-edition/store/documentWriteAudit.test.ts b/src/lib/ai-edition/store/documentWriteAudit.test.ts
index 6860921d7..0f0065152 100644
--- a/src/lib/ai-edition/store/documentWriteAudit.test.ts
+++ b/src/lib/ai-edition/store/documentWriteAudit.test.ts
@@ -241,11 +241,10 @@ const DECLARED: WritePath[] = [
 	w("src/lib/ai-edition/store/useTimeline.ts", "insertClipAt", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "moveClip", "save", "gesture"),
 	// Imported audio tracks (issue #350). Each is a direct user edit — drag/trim the
-	// track, change its level, mute it, or delete it — one undo step apiece.
-	w("src/lib/ai-edition/store/useTimeline.ts", "moveAudioTrack", "save", "gesture"),
+	// track (placeAudioTrack), change its level, mute it, or delete it — one undo
+	// step apiece.
 	w("src/lib/ai-edition/store/useTimeline.ts", "placeAudioTrack", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "removeAudioTrack", "save", "gesture"),
-	w("src/lib/ai-edition/store/useTimeline.ts", "resizeAudioTrack", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "setAudioTrackGain", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "toggleAudioTrackMute", "save", "gesture"),
 	// The round-2 defect: a background duration probe every freshly imported asset
diff --git a/src/lib/ai-edition/store/useTimeline.test.ts b/src/lib/ai-edition/store/useTimeline.test.ts
index 45a59b9eb..0fca8c68e 100644
--- a/src/lib/ai-edition/store/useTimeline.test.ts
+++ b/src/lib/ai-edition/store/useTimeline.test.ts
@@ -1358,17 +1358,19 @@ describe("useTimeline audio tracks", () => {
 		expect(useProjectStore.getState().document?.audioTracks).toEqual([]);
 	});
 
-	it("move / trim / gain / mute update the track and each is one undo step", async () => {
+	it("place / gain / mute update the track and each is one undo step", async () => {
 		const { result } = renderTimeline();
 		let id = "";
 		await act(async () => {
 			id = (await result.current.addAudioTrack("audio_1", 2)) ?? "";
 		});
+		// A lane drag commits position and trim together (see placeAudioTrack).
 		await act(async () => {
-			await result.current.moveAudioTrack(id, 9);
-		});
-		await act(async () => {
-			await result.current.resizeAudioTrack(id, { trimStartSec: 1, trimEndSec: 8 });
+			await result.current.placeAudioTrack(id, {
+				timelineStartSec: 9,
+				trimStartSec: 1,
+				trimEndSec: 8,
+			});
 		});
 		await act(async () => {
 			await result.current.setAudioTrackGain(id, -6);
@@ -1386,7 +1388,7 @@ describe("useTimeline audio tracks", () => {
 			mute: true,
 		});
 
-		// Five writes (add + four edits) → the mute undoes first.
+		// Four writes (add + three edits) → the mute undoes first.
 		act(() => {
 			expect(undo()).toBe(true);
 		});
diff --git a/src/lib/ai-edition/store/useTimeline.ts b/src/lib/ai-edition/store/useTimeline.ts
index c9ac89b1b..db58c38fa 100644
--- a/src/lib/ai-edition/store/useTimeline.ts
+++ b/src/lib/ai-edition/store/useTimeline.ts
@@ -8,12 +8,10 @@ import { toFileUrl } from "@/components/video-editor/projectPersistence";
 import type { AnnotationRegion, AnnotationType } from "@/components/video-editor/types";
 import { useScopedT } from "@/contexts/I18nContext";
 import {
-	moveAudioTrack as moveAudioTrackInDocument,
 	removeAudioTrack as removeAudioTrackInDocument,
 	setAudioTrackGain as setAudioTrackGainInDocument,
 	setAudioTrackMute as setAudioTrackMuteInDocument,
 	setAudioTrackPlacement as setAudioTrackPlacementInDocument,
-	setAudioTrackTrim as setAudioTrackTrimInDocument,
 } from "../document/audioTracks";
 import { createId } from "../document/ids";
 import {
@@ -1228,27 +1226,6 @@ export function useTimeline() {
 		[document, saveDocument, selectedAudioTrackId, setSelectedAudioTrackId],
 	);
 
-	// Drag-reposition the track's head. `timelineStartSec` is output-timeline time.
-	const moveAudioTrack = useCallback(
-		async (trackId: string, timelineStartSec: number) => {
-			if (!document) return;
-			await saveDocument(moveAudioTrackInDocument(document, trackId, timelineStartSec), {
-				history: true,
-			});
-		},
-		[document, saveDocument],
-	);
-
-	// Edge-drag trim: window the source file (source seconds). Pass
-	// `trimEndSec: undefined` to clear the tail trim.
-	const resizeAudioTrack = useCallback(
-		async (trackId: string, trim: { trimStartSec: number; trimEndSec?: number }) => {
-			if (!document) return;
-			await saveDocument(setAudioTrackTrimInDocument(document, trackId, trim), { history: true });
-		},
-		[document, saveDocument],
-	);
-
 	// The commit for a lane drag: position and trim in one write (one undo step).
 	// A left-edge drag moves both timelineStartSec and trimStartSec, which two
 	// separate ops could not do atomically. See setAudioTrackPlacement.
@@ -1308,8 +1285,6 @@ export function useTimeline() {
 		removeRegions,
 		addAudioTrack,
 		removeAudioTrack,
-		moveAudioTrack,
-		resizeAudioTrack,
 		placeAudioTrack,
 		setAudioTrackGain,
 		toggleAudioTrackMute,

From f7c406273acd8f5cb570d5552f14b162268768be Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 13:25:28 +0200
Subject: [PATCH 15/20] refactor(editor): remove the mute feature from imported
 audio tracks
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The mute button was removed during UI review, leaving mute reachable nowhere
— a working-but-unsettable flag with a dead branch in the Rust mixer. It was
added on this branch and never shipped, so it comes out cleanly with no
schema migration. Volume (down to -12 dB) plus delete cover the need for a
simple audio overlay; a mute+solo pass can come back as its own feature.

Removed end-to-end: audioTrackSchema.mute, setAudioTrackMute /
toggleAudioTrackMute, the pill's mute glyph + .laneAudioMuted, the preview's
mute gate, the scene's mute field (TS + scene.rs), the mixer's mute skip,
and every test that exercised it. Rust (cargo test --lib audio, 14) and TS
(1049 across ai-edition + native) pass; compositor addon rebuilt.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 crates/compositor/src/audio.rs                | 42 +++++++------------
 crates/compositor/src/scene.rs                |  2 -
 .../ai-edition/VirtualPreview.audio.test.ts   |  9 ----
 .../VirtualPreview.playback.test.tsx          |  1 -
 src/components/ai-edition/VirtualPreview.tsx  |  8 ++--
 .../ai-edition/v4/EditorShellV4.module.css    |  3 --
 .../v4/V4Timeline.geometry.test.tsx           |  1 -
 src/components/ai-edition/v4/V4Timeline.tsx   |  5 +--
 .../ai-edition/document/audioTracks.test.ts   |  9 ----
 src/lib/ai-edition/document/audioTracks.ts    |  9 ----
 src/lib/ai-edition/schema/index.test.ts       |  3 +-
 src/lib/ai-edition/schema/index.ts            |  5 +--
 .../store/documentWriteAudit.test.ts          |  4 +-
 src/lib/ai-edition/store/useTimeline.test.ts  | 10 ++---
 src/lib/ai-edition/store/useTimeline.ts       | 14 -------
 src/native/sceneDescription.test.ts           |  2 -
 src/native/sceneDescription.ts                |  2 -
 17 files changed, 27 insertions(+), 102 deletions(-)

diff --git a/crates/compositor/src/audio.rs b/crates/compositor/src/audio.rs
index ddd809bbd..f8637edaa 100644
--- a/crates/compositor/src/audio.rs
+++ b/crates/compositor/src/audio.rs
@@ -923,19 +923,16 @@ pub fn assemble_concatenated_pcm(
 /// track that runs past the video is truncated to it, so the audio and video
 /// streams stay the same length for the muxer.
 ///
-/// A muted track, or one whose file has no decodable audio, is skipped — the same
-/// degradation a stream-less clip gets. `trim_end_sec` must be concrete (the
-/// renderer sends `trimEnd ?? durationSec`): `decode_clip_audio` preallocates from
-/// it, so an unbounded end would try to allocate the whole real line.
+/// A track whose file has no decodable audio is skipped — the same degradation a
+/// stream-less clip gets. `trim_end_sec` must be concrete (the renderer sends
+/// `trimEnd ?? durationSec`): `decode_clip_audio` preallocates from it, so an
+/// unbounded end would try to allocate the whole real line.
 pub fn mix_external_tracks(mut programme: PlanarPcm, tracks: &[SceneAudioTrack]) -> PlanarPcm {
     let programme_len = programme.first().map(Vec::len).unwrap_or(0);
     if programme_len == 0 {
         return programme;
     }
     for track in tracks {
-        if track.mute {
-            continue;
-        }
         let trim_start = track.trim_start_sec.max(0.0);
         let Some(trim_end) = track.trim_end_sec else {
             // Without a concrete end there is no safe window to decode (see the doc
@@ -1135,28 +1132,17 @@ mod tests {
     }
 
     #[test]
-    fn mix_external_tracks_skips_muted_and_empty_windows() {
+    fn mix_external_tracks_skips_empty_windows() {
         let programme = planar(&[0.4, 0.4]);
-        let tracks = vec![
-            SceneAudioTrack {
-                path: "/nope.mp3".into(),
-                start_sec: 0.0,
-                gain_db: 0.0,
-                trim_start_sec: 0.0,
-                trim_end_sec: Some(1.0),
-                mute: true,
-            },
-            SceneAudioTrack {
-                path: "/nope.mp3".into(),
-                start_sec: 0.0,
-                gain_db: 0.0,
-                trim_start_sec: 2.0,
-                trim_end_sec: Some(1.0), // end <= start: empty window, never decoded
-                mute: false,
-            },
-        ];
-        // Both tracks are skipped before any decode, so the programme is untouched
-        // even though the path does not exist.
+        let tracks = vec![SceneAudioTrack {
+            path: "/nope.mp3".into(),
+            start_sec: 0.0,
+            gain_db: 0.0,
+            trim_start_sec: 2.0,
+            trim_end_sec: Some(1.0), // end <= start: empty window, never decoded
+        }];
+        // The empty window is skipped before any decode, so the programme is
+        // untouched even though the path does not exist.
         let out = mix_external_tracks(programme, &tracks);
         assert_eq!(out[0], vec![0.4, 0.4]);
     }
diff --git a/crates/compositor/src/scene.rs b/crates/compositor/src/scene.rs
index 822e0d5bc..a9fc994f8 100644
--- a/crates/compositor/src/scene.rs
+++ b/crates/compositor/src/scene.rs
@@ -441,8 +441,6 @@ pub struct SceneAudioTrack {
     pub trim_start_sec: f64,
     #[serde(default)]
     pub trim_end_sec: Option<f64>,
-    #[serde(default)]
-    pub mute: bool,
 }
 
 #[derive(Debug, Clone, Copy, Deserialize)]
diff --git a/src/components/ai-edition/VirtualPreview.audio.test.ts b/src/components/ai-edition/VirtualPreview.audio.test.ts
index c8e38beff..aeb2781e8 100644
--- a/src/components/ai-edition/VirtualPreview.audio.test.ts
+++ b/src/components/ai-edition/VirtualPreview.audio.test.ts
@@ -93,7 +93,6 @@ describe("resolveTimelineAudioPlayback", () => {
 		trimStartSec: 2,
 		trimEndSec: 8,
 		gainDb: 0,
-		mute: false,
 		label: "",
 	};
 
@@ -114,14 +113,6 @@ describe("resolveTimelineAudioPlayback", () => {
 		});
 	});
 
-	it("never plays while muted, even inside its window", () => {
-		const muted = { ...track, mute: true };
-		expect(resolveTimelineAudioPlayback(13, muted)).toEqual({
-			targetTimeSec: 5,
-			shouldPlay: false,
-		});
-	});
-
 	it("uses the asset duration as the out-point when the tail isn't trimmed", () => {
 		const untrimmed = { ...track, trimStartSec: 0, trimEndSec: undefined, durationSec: 5 };
 		// Span is 10..15. At 14 → 4s of source, still playing.
diff --git a/src/components/ai-edition/VirtualPreview.playback.test.tsx b/src/components/ai-edition/VirtualPreview.playback.test.tsx
index d6b2d9f6c..ae195532f 100644
--- a/src/components/ai-edition/VirtualPreview.playback.test.tsx
+++ b/src/components/ai-edition/VirtualPreview.playback.test.tsx
@@ -247,7 +247,6 @@ describe("VirtualPreview imported audio tracks", () => {
 		trimStartSec: 1,
 		trimEndSec: 3,
 		gainDb: 0,
-		mute: false,
 		label: "",
 	};
 
diff --git a/src/components/ai-edition/VirtualPreview.tsx b/src/components/ai-edition/VirtualPreview.tsx
index eb9e83943..00b17bc0e 100644
--- a/src/components/ai-edition/VirtualPreview.tsx
+++ b/src/components/ai-edition/VirtualPreview.tsx
@@ -76,9 +76,9 @@ export function resolveAudioTrackPlayback(
  *
  * A track occupies `[timelineStartSec, timelineStartSec + (trimEnd - trimStart)]`
  * on the timeline; its source position is `trimStart` plus however far the
- * playhead is into that span. Outside the span — or when muted — it parks at the
- * nearer trim edge and stays paused, the same discipline `resolveAudioTrackPlayback`
- * uses so the rAF never seeks an element into nothing.
+ * playhead is into that span. Outside the span it parks at the nearer trim edge
+ * and stays paused, the same discipline `resolveAudioTrackPlayback` uses so the
+ * rAF never seeks an element into nothing.
  *
  * This is the RAW/document timeline the ruler, playhead and lane all use — NOT
  * the trim-compressed output timeline — because that is where the track was
@@ -92,7 +92,7 @@ export function resolveTimelineAudioPlayback(virtualTimeSec: number, track: Axcu
 	const local = virtualTimeSec - track.timelineStartSec;
 	return {
 		targetTimeSec: Math.min(Math.max(trimStart, trimStart + local), trimEnd),
-		shouldPlay: !track.mute && local >= 0 && local < windowLen,
+		shouldPlay: local >= 0 && local < windowLen,
 	};
 }
 
diff --git a/src/components/ai-edition/v4/EditorShellV4.module.css b/src/components/ai-edition/v4/EditorShellV4.module.css
index 2096aa159..0a72c761b 100644
--- a/src/components/ai-edition/v4/EditorShellV4.module.css
+++ b/src/components/ai-edition/v4/EditorShellV4.module.css
@@ -1509,9 +1509,6 @@
 .laneAudio:active {
 	cursor: pointer;
 }
-.laneAudioMuted {
-	opacity: 0.5;
-}
 /* The label rides above the waveform (which is inset:0 behind it). */
 .laneAudioLabel {
 	position: relative;
diff --git a/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx b/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx
index 750e1f689..0ece54317 100644
--- a/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.geometry.test.tsx
@@ -357,7 +357,6 @@ describe("V4Timeline audio lane drag", () => {
 		trimStartSec: 0,
 		trimEndSec: undefined as number | undefined,
 		gainDb: 0,
-		mute: false,
 		label: "vo",
 	});
 
diff --git a/src/components/ai-edition/v4/V4Timeline.tsx b/src/components/ai-edition/v4/V4Timeline.tsx
index 9fcfbf48e..cff3eb60e 100644
--- a/src/components/ai-edition/v4/V4Timeline.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.tsx
@@ -10,7 +10,6 @@ import {
 	Sparkles,
 	SplitSquareHorizontal,
 	Trash2,
-	VolumeX,
 	Wand2,
 	ZoomIn,
 } from "lucide-react";
@@ -374,7 +373,7 @@ const AudioLanePill = memo(function AudioLanePill({
 			tabIndex={0}
 			className={`${styles.lanePill} ${styles.laneAudio}${
 				selected ? ` ${styles.lanePillSel}` : ""
-			}${track.mute ? ` ${styles.laneAudioMuted}` : ""}`}
+			}`}
 			style={{ left: `${leftPct}%`, width: `${widthPct}%`, minWidth: 3 }}
 			// Body drag moves the track; it also selects and stops the .tlTracks scrub.
 			onPointerDown={(e) => onStartDrag(e, track, "move")}
@@ -399,7 +398,7 @@ const AudioLanePill = memo(function AudioLanePill({
 				gain={audioGainScalar(track.gainDb)}
 			/>
 			<span className={styles.laneAudioLabel}>
-				{track.mute ? <VolumeX size={11} /> : <Music size={11} />}
+				<Music size={11} />
 				{label}
 			</span>
 			<span
diff --git a/src/lib/ai-edition/document/audioTracks.test.ts b/src/lib/ai-edition/document/audioTracks.test.ts
index cddee21dd..ddec1ce05 100644
--- a/src/lib/ai-edition/document/audioTracks.test.ts
+++ b/src/lib/ai-edition/document/audioTracks.test.ts
@@ -4,7 +4,6 @@ import {
 	appendAudioTrack,
 	removeAudioTrack,
 	setAudioTrackGain,
-	setAudioTrackMute,
 	setAudioTrackPlacement,
 } from "./audioTracks";
 
@@ -36,14 +35,6 @@ describe("audioTracks document ops (issue #350)", () => {
 		expect(setAudioTrackGain(doc, track.id, Number.NaN).audioTracks[0]?.gainDb).toBe(0);
 	});
 
-	it("setAudioTrackMute toggles mute without touching gain", () => {
-		const { doc, track } = docWithTrack();
-		const withGain = setAudioTrackGain(doc, track.id, -3);
-		const muted = setAudioTrackMute(withGain, track.id, true);
-		expect(muted.audioTracks[0]?.mute).toBe(true);
-		expect(muted.audioTracks[0]?.gainDb).toBe(-3);
-	});
-
 	it("setAudioTrackPlacement writes position and trim together, staying schema-valid", () => {
 		const { doc, track } = docWithTrack();
 		const placed = setAudioTrackPlacement(doc, track.id, {
diff --git a/src/lib/ai-edition/document/audioTracks.ts b/src/lib/ai-edition/document/audioTracks.ts
index 5fb49c55b..a70042f59 100644
--- a/src/lib/ai-edition/document/audioTracks.ts
+++ b/src/lib/ai-edition/document/audioTracks.ts
@@ -72,12 +72,3 @@ export function setAudioTrackGain(
 ): AxcutDocument {
 	return updateAudioTrack(doc, trackId, (t) => ({ ...t, gainDb: finite(gainDb) }));
 }
-
-/** Mute or unmute a track without losing its stored gain. */
-export function setAudioTrackMute(
-	doc: AxcutDocument,
-	trackId: string,
-	mute: boolean,
-): AxcutDocument {
-	return updateAudioTrack(doc, trackId, (t) => ({ ...t, mute }));
-}
diff --git a/src/lib/ai-edition/schema/index.test.ts b/src/lib/ai-edition/schema/index.test.ts
index 2c6b25be4..2e69c6a42 100644
--- a/src/lib/ai-edition/schema/index.test.ts
+++ b/src/lib/ai-edition/schema/index.test.ts
@@ -975,7 +975,7 @@ describe("v6 -> v7 trim clip-anchor migration", () => {
 });
 
 describe("audio tracks (issue #350)", () => {
-	it("applies defaults for gain, mute, trim, position, and label", () => {
+	it("applies defaults for gain, trim, position, and label", () => {
 		const track = audioTrackSchema.parse({
 			id: "audio_1",
 			assetId: "asset_1",
@@ -985,7 +985,6 @@ describe("audio tracks (issue #350)", () => {
 		expect(track.trimStartSec).toBe(0);
 		expect(track.trimEndSec).toBeUndefined();
 		expect(track.gainDb).toBe(0);
-		expect(track.mute).toBe(false);
 		expect(track.label).toBe("");
 	});
 
diff --git a/src/lib/ai-edition/schema/index.ts b/src/lib/ai-edition/schema/index.ts
index e2449f44c..00967f3d8 100644
--- a/src/lib/ai-edition/schema/index.ts
+++ b/src/lib/ai-edition/schema/index.ts
@@ -491,7 +491,7 @@ export const zoomRegionSchema = endGteStart(
 //
 // `assetId` points at an asset with `kind: "audio"`. `timelineStartSec` places
 // the track's head; `trimStartSec`/`trimEndSec` window the source file (both in
-// source seconds); `gainDb` + `mute` set its level.
+// source seconds); `gainDb` sets its level.
 export const audioTrackSchema = z
 	.object({
 		id: z.string().min(1),
@@ -505,7 +505,6 @@ export const audioTrackSchema = z
 		// the tail so the pill and the export agree on where the track stops.
 		trimEndSec: z.number().nonnegative().optional(),
 		gainDb: z.number().default(0),
-		mute: z.boolean().default(false),
 		label: z.string().default(""),
 	})
 	.refine((data) => data.trimEndSec === undefined || data.trimEndSec >= data.trimStartSec, {
@@ -1042,7 +1041,7 @@ export function ensureDocument(value: unknown): AxcutDocument {
  * Build a timeline audio track for an imported audio asset (issue #350). The
  * head is placed at `timelineStartSec` (output-timeline seconds) and the track
  * spans the whole source file until the user trims it. Parsed through the schema
- * so every default (gain, mute, trim) is applied in one place.
+ * so every default (gain, trim) is applied in one place.
  */
 export function createAudioTrack(input: {
 	assetId: string;
diff --git a/src/lib/ai-edition/store/documentWriteAudit.test.ts b/src/lib/ai-edition/store/documentWriteAudit.test.ts
index 0f0065152..3641782fb 100644
--- a/src/lib/ai-edition/store/documentWriteAudit.test.ts
+++ b/src/lib/ai-edition/store/documentWriteAudit.test.ts
@@ -241,12 +241,10 @@ const DECLARED: WritePath[] = [
 	w("src/lib/ai-edition/store/useTimeline.ts", "insertClipAt", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "moveClip", "save", "gesture"),
 	// Imported audio tracks (issue #350). Each is a direct user edit — drag/trim the
-	// track (placeAudioTrack), change its level, mute it, or delete it — one undo
-	// step apiece.
+	// track (placeAudioTrack), change its level, or delete it — one undo step apiece.
 	w("src/lib/ai-edition/store/useTimeline.ts", "placeAudioTrack", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "removeAudioTrack", "save", "gesture"),
 	w("src/lib/ai-edition/store/useTimeline.ts", "setAudioTrackGain", "save", "gesture"),
-	w("src/lib/ai-edition/store/useTimeline.ts", "toggleAudioTrackMute", "save", "gesture"),
 	// The round-2 defect: a background duration probe every freshly imported asset
 	// fires, because `addAsset` never populates `durationSec`.
 	w("src/lib/ai-edition/store/useTimeline.ts", "probeAndCorrectClip", "save", "automatic"),
diff --git a/src/lib/ai-edition/store/useTimeline.test.ts b/src/lib/ai-edition/store/useTimeline.test.ts
index 0fca8c68e..c79ec343f 100644
--- a/src/lib/ai-edition/store/useTimeline.test.ts
+++ b/src/lib/ai-edition/store/useTimeline.test.ts
@@ -1358,7 +1358,7 @@ describe("useTimeline audio tracks", () => {
 		expect(useProjectStore.getState().document?.audioTracks).toEqual([]);
 	});
 
-	it("place / gain / mute update the track and each is one undo step", async () => {
+	it("place / gain update the track and each is one undo step", async () => {
 		const { result } = renderTimeline();
 		let id = "";
 		await act(async () => {
@@ -1375,9 +1375,6 @@ describe("useTimeline audio tracks", () => {
 		await act(async () => {
 			await result.current.setAudioTrackGain(id, -6);
 		});
-		await act(async () => {
-			await result.current.toggleAudioTrackMute(id);
-		});
 
 		const track = useProjectStore.getState().document?.audioTracks[0];
 		expect(track).toMatchObject({
@@ -1385,14 +1382,13 @@ describe("useTimeline audio tracks", () => {
 			trimStartSec: 1,
 			trimEndSec: 8,
 			gainDb: -6,
-			mute: true,
 		});
 
-		// Four writes (add + three edits) → the mute undoes first.
+		// Three writes (add + place + gain) → the gain edit undoes first.
 		act(() => {
 			expect(undo()).toBe(true);
 		});
-		expect(useProjectStore.getState().document?.audioTracks[0]?.mute).toBe(false);
+		expect(useProjectStore.getState().document?.audioTracks[0]?.gainDb).toBe(0);
 	});
 
 	it("removeAudioTrack deletes the track", async () => {
diff --git a/src/lib/ai-edition/store/useTimeline.ts b/src/lib/ai-edition/store/useTimeline.ts
index db58c38fa..aed880208 100644
--- a/src/lib/ai-edition/store/useTimeline.ts
+++ b/src/lib/ai-edition/store/useTimeline.ts
@@ -10,7 +10,6 @@ import { useScopedT } from "@/contexts/I18nContext";
 import {
 	removeAudioTrack as removeAudioTrackInDocument,
 	setAudioTrackGain as setAudioTrackGainInDocument,
-	setAudioTrackMute as setAudioTrackMuteInDocument,
 	setAudioTrackPlacement as setAudioTrackPlacementInDocument,
 } from "../document/audioTracks";
 import { createId } from "../document/ids";
@@ -1250,18 +1249,6 @@ export function useTimeline() {
 		[document, saveDocument],
 	);
 
-	const toggleAudioTrackMute = useCallback(
-		async (trackId: string) => {
-			if (!document) return;
-			const track = document.audioTracks.find((t) => t.id === trackId);
-			if (!track) return;
-			await saveDocument(setAudioTrackMuteInDocument(document, trackId, !track.mute), {
-				history: true,
-			});
-		},
-		[document, saveDocument],
-	);
-
 	return {
 		zoomRegions: document?.zoomRanges ?? [],
 		trimRanges: document?.timeline.trimRanges ?? [],
@@ -1287,7 +1274,6 @@ export function useTimeline() {
 		removeAudioTrack,
 		placeAudioTrack,
 		setAudioTrackGain,
-		toggleAudioTrackMute,
 		selectedAudioTrackId,
 		selectAudioTrack,
 		selectRegion,
diff --git a/src/native/sceneDescription.test.ts b/src/native/sceneDescription.test.ts
index 0802f8d60..5d666c87c 100644
--- a/src/native/sceneDescription.test.ts
+++ b/src/native/sceneDescription.test.ts
@@ -1806,7 +1806,6 @@ describe("buildSceneDescription.audioTracks", () => {
 		trimStartSec: 2,
 		trimEndSec: 12 as number | undefined,
 		gainDb: -3,
-		mute: false,
 		label: "",
 	};
 
@@ -1819,7 +1818,6 @@ describe("buildSceneDescription.audioTracks", () => {
 				gainDb: -3,
 				trimStartSec: 2,
 				trimEndSec: 12,
-				mute: false,
 			},
 		]);
 	});
diff --git a/src/native/sceneDescription.ts b/src/native/sceneDescription.ts
index 3d1100ad6..8ee9e3e07 100644
--- a/src/native/sceneDescription.ts
+++ b/src/native/sceneDescription.ts
@@ -406,7 +406,6 @@ export interface SceneDescription {
 		gainDb: number;
 		trimStartSec: number;
 		trimEndSec: number;
-		mute: boolean;
 	}>;
 	/**
 	 * Per-clip screen crop (fractions of the frame), or null for the identity
@@ -481,7 +480,6 @@ export function buildSceneDescription(
 				gainDb: track.gainDb,
 				trimStartSec: track.trimStartSec,
 				trimEndSec,
-				mute: track.mute,
 			},
 		];
 	});

From 1cc8f0e5baca5d3a3e58db747831529929be56eb Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 15:55:15 +0200
Subject: [PATCH 16/20] docs: list audioTracks[] in the document-model
 top-level shape

Phase 7 leftover for issue #350: the top-level-shape table enumerated every
other document array but not the new audioTracks[]. Add the row.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 technical-documentation/architecture/document-model.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/technical-documentation/architecture/document-model.md b/technical-documentation/architecture/document-model.md
index c312ad605..ea5e76c88 100644
--- a/technical-documentation/architecture/document-model.md
+++ b/technical-documentation/architecture/document-model.md
@@ -27,6 +27,7 @@ and anything unknown is rejected by the `z.literal(axcutSchemaVersion)` check in
 | `timeline` | `{ clips[], gaps[], trimRanges[], muteRanges[], speedRanges[], captionRanges[] }` | Clips carry their own in/out (`sourceStartSec`/`sourceEndSec`); trims are anchored to a clip (`clipId?`) since v7. See [timeline-model.md](timeline-model.md). |
 | `annotations[]` | `AxcutAnnotationRegion[]` | Text/image/figure/blur overlays, anchored to a clip (`clipId?`). |
 | `zoomRanges[]` | `AxcutZoomRegion[]` | Zoom-in effects, depth 1–6, anchored to a clip (`clipId?`). |
+| `audioTracks[]` | `AxcutAudioTrack[]` | Imported audio (voiceover / BGM / SFX, issue #350) mixed over the programme. NOT clip-anchored — addressed in RAW/document timeline seconds (`timelineStartSec`), with `trimStartSec`/`trimEndSec` windowing the source and `gainDb` its level. Added from the timeline toolbar; the referenced asset has `kind: "audio"`. |
 | `legacyEditor` | OpenScreen v2 `ProjectEditorState` passthrough | Appearance/cursor settings not yet first-class in the AI-edition schema. |
 | `agent` | `{ baseIntent?, pendingQuestions[], suggestions[], lastAppliedOperations[], lastReasoningSummary? }` | LLM agent state. |
 | `preview` | `{ strategy: "seek" \| "mse-proxy", revision: number }` | `revision` is the bump used to invalidate cached frames after an edit. |

From 73c1e4d3070862b86f34ebef6df640f2918c2b85 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 17:55:45 +0200
Subject: [PATCH 17/20] fix(editor): address CodeRabbit review on the
 audio-import PR (#502)
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Correctness / data integrity:
- audio.rs: bound the decode window to the programme remainder and skip a
  track that starts past the end, so a long track pinned near a short
  export can't buffer hours of PCM (then discard it).
- document-service.removeAsset: pass primary to the next VIDEO asset, never
  an audio overlay, and drop audioTracks that referenced the removed asset.
- useTimeline: backfill a missing audio duration on load (a failed
  import-time probe otherwise leaves durationSec 0 → a zero-length, never-
  playing window), mirroring the video-dimension backfill.
- projectStore.importAudioAsset: report failure when track placement fails,
  instead of claiming a successful one-shot import with no track.
- V4Timeline: clamp the drag so a track's head/tail stay within the
  programme (no pill past 100%, matching the export's truncation).
- useTimeline: clear region/clip selection after a successful audio-track
  insert (no concurrent selections); clear the inspector selection only
  AFTER a delete commits.

Tests / quality:
- Remove a new `any` cast in projectStore.test (use vi.mocked).
- Translate the audioTrack / selectAudio / audioFiles strings in all 12
  non-English locales.
- Add coverage: removeAsset audio cases, the duration backfill, browser-shim
  audio import, and the decode-bound skip (Rust).

Deferred with rationale (noted on the PR): schema v8 bump (audioTracks
follows the repo's additive-no-bump precedent, transcriptionFailure);
positive-gain preview via WebAudio nodes (heavy, risks the audio graph);
moving audioTracksRef to an effect (matches the file's existing render-ref
idiom).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 crates/compositor/src/audio.rs                | 43 +++++++++--
 electron/ai-edition/document-service.test.ts  | 44 +++++++++++
 electron/ai-edition/document-service.ts       |  9 ++-
 src/components/ai-edition/v4/V4Timeline.tsx   | 12 ++-
 src/i18n/locales/ar/dialogs.json              |  4 +-
 src/i18n/locales/ar/settings.json             | 10 +--
 src/i18n/locales/es/dialogs.json              |  4 +-
 src/i18n/locales/es/settings.json             | 10 +--
 src/i18n/locales/fr/dialogs.json              |  4 +-
 src/i18n/locales/fr/settings.json             | 10 +--
 src/i18n/locales/it/dialogs.json              |  4 +-
 src/i18n/locales/it/settings.json             | 10 +--
 src/i18n/locales/ja-JP/dialogs.json           |  4 +-
 src/i18n/locales/ja-JP/settings.json          | 10 +--
 src/i18n/locales/ko-KR/dialogs.json           |  4 +-
 src/i18n/locales/ko-KR/settings.json          | 10 +--
 src/i18n/locales/pt-BR/dialogs.json           |  4 +-
 src/i18n/locales/pt-BR/settings.json          | 10 +--
 src/i18n/locales/ru/dialogs.json              |  4 +-
 src/i18n/locales/ru/settings.json             | 10 +--
 src/i18n/locales/tr/dialogs.json              |  4 +-
 src/i18n/locales/tr/settings.json             | 10 +--
 src/i18n/locales/vi/dialogs.json              |  4 +-
 src/i18n/locales/vi/settings.json             | 10 +--
 src/i18n/locales/zh-CN/dialogs.json           |  4 +-
 src/i18n/locales/zh-CN/settings.json          | 10 +--
 src/i18n/locales/zh-TW/dialogs.json           |  4 +-
 src/i18n/locales/zh-TW/settings.json          | 10 +--
 .../store/documentWriteAudit.test.ts          |  3 +
 src/lib/ai-edition/store/projectStore.test.ts |  3 +-
 src/lib/ai-edition/store/projectStore.ts      |  7 +-
 src/lib/ai-edition/store/useTimeline.test.ts  | 50 ++++++++++++
 src/lib/ai-edition/store/useTimeline.ts       | 76 +++++++++++++++++--
 src/native/browserShim.test.ts                | 60 +++++++++++++++
 34 files changed, 373 insertions(+), 102 deletions(-)
 create mode 100644 src/native/browserShim.test.ts

diff --git a/crates/compositor/src/audio.rs b/crates/compositor/src/audio.rs
index f8637edaa..f4d0ea819 100644
--- a/crates/compositor/src/audio.rs
+++ b/crates/compositor/src/audio.rs
@@ -923,23 +923,40 @@ pub fn assemble_concatenated_pcm(
 /// track that runs past the video is truncated to it, so the audio and video
 /// streams stay the same length for the muxer.
 ///
+/// The decode window is capped up front at the room left in the programme after
+/// `start_sec`, and a track starting at/after the end is skipped without decoding.
+/// `decode_clip_audio` preallocates from the window, so this keeps a long track
+/// pinned near a short programme's end from buffering (and clamping away) hours of
+/// PCM. `trim_end_sec` must therefore be concrete — the renderer sends
+/// `trimEnd ?? durationSec`.
+///
 /// A track whose file has no decodable audio is skipped — the same degradation a
-/// stream-less clip gets. `trim_end_sec` must be concrete (the renderer sends
-/// `trimEnd ?? durationSec`): `decode_clip_audio` preallocates from it, so an
-/// unbounded end would try to allocate the whole real line.
+/// stream-less clip gets.
 pub fn mix_external_tracks(mut programme: PlanarPcm, tracks: &[SceneAudioTrack]) -> PlanarPcm {
     let programme_len = programme.first().map(Vec::len).unwrap_or(0);
     if programme_len == 0 {
         return programme;
     }
     for track in tracks {
+        let offset = (track.start_sec.max(0.0) * AUDIO_OUTPUT_SAMPLE_RATE as f64).round() as usize;
+        // A track that starts at or past the programme end contributes nothing —
+        // skip it before decoding anything.
+        if offset >= programme_len {
+            continue;
+        }
         let trim_start = track.trim_start_sec.max(0.0);
-        let Some(trim_end) = track.trim_end_sec else {
+        let Some(trim_end_full) = track.trim_end_sec else {
             // Without a concrete end there is no safe window to decode (see the doc
             // comment); the renderer always resolves one, so this only guards a
             // hand-written scene.
             continue;
         };
+        // Cap the decode window at the room left in the programme. Everything past
+        // `offset` that overflows is discarded by `overlay_track_pcm` anyway, so
+        // decoding it only wastes time and memory — a three-hour track placed at
+        // second 9 of a ten-second export must not buffer three hours of PCM.
+        let remaining_sec = (programme_len - offset) as f64 / AUDIO_OUTPUT_SAMPLE_RATE as f64;
+        let trim_end = trim_end_full.min(trim_start + remaining_sec);
         if trim_end <= trim_start {
             continue;
         }
@@ -948,7 +965,6 @@ pub fn mix_external_tracks(mut programme: PlanarPcm, tracks: &[SceneAudioTrack])
             _ => continue,
         };
         let gain = 10.0f32.powf(track.gain_db.clamp(-12.0, 12.0) / 20.0);
-        let offset = (track.start_sec.max(0.0) * AUDIO_OUTPUT_SAMPLE_RATE as f64).round() as usize;
         overlay_track_pcm(&mut programme, &decoded, offset, gain);
     }
     programme
@@ -1147,6 +1163,23 @@ mod tests {
         assert_eq!(out[0], vec![0.4, 0.4]);
     }
 
+    #[test]
+    fn mix_external_tracks_skips_a_track_that_starts_past_the_programme() {
+        // 2 samples = ~0.00004 s of programme at 48 kHz; the track starts at 1 s, so
+        // its offset is past the end. It must be skipped before any decode is
+        // attempted (the path does not exist), never buffering its window.
+        let programme = planar(&[0.4, 0.4]);
+        let tracks = vec![SceneAudioTrack {
+            path: "/nope.mp3".into(),
+            start_sec: 1.0,
+            gain_db: 0.0,
+            trim_start_sec: 0.0,
+            trim_end_sec: Some(3600.0),
+        }];
+        let out = mix_external_tracks(programme, &tracks);
+        assert_eq!(out[0], vec![0.4, 0.4]);
+    }
+
     #[test]
     fn single_track_is_not_clamped() {
         // Promesse de non-régression : une source mono-piste ressort telle quelle, y compris
diff --git a/electron/ai-edition/document-service.test.ts b/electron/ai-edition/document-service.test.ts
index 91e780acf..91448d350 100644
--- a/electron/ai-edition/document-service.test.ts
+++ b/electron/ai-edition/document-service.test.ts
@@ -405,6 +405,50 @@ describe("DocumentService", () => {
 			expect(after.project.primaryAssetId).toBe(b.assets[1]?.id);
 		});
 
+		// Issue #350 — an audio overlay can never be primary.
+		it("passes primary to the next VIDEO asset, never to an audio asset", async () => {
+			const doc = await service.createProject("P");
+			const video = await service.addAsset(doc.project.id, { path: "/tmp/screen.mp4" });
+			await service.addAsset(doc.project.id, { path: "/tmp/music.mp3", kind: "audio" });
+			const primaryId = video.project.primaryAssetId;
+			expect(primaryId).toBeTruthy();
+			// Removing the only video leaves just the audio asset; primary must clear,
+			// not fall to the audio one.
+			const after = await service.removeAsset(doc.project.id, primaryId ?? "");
+			expect(after.project.primaryAssetId).toBeUndefined();
+			expect(after.assets).toHaveLength(1);
+			expect(after.assets[0]?.kind).toBe("audio");
+		});
+
+		it("drops audioTracks that referenced a removed audio asset", async () => {
+			const doc = await service.createProject("P");
+			await service.addAsset(doc.project.id, { path: "/tmp/screen.mp4" });
+			const withAudio = await service.addAsset(doc.project.id, {
+				path: "/tmp/music.mp3",
+				kind: "audio",
+			});
+			const audioId = withAudio.assets.find((a) => a.kind === "audio")?.id ?? "";
+			expect(audioId).toBeTruthy();
+			const withTrack = await service.saveProject({
+				...withAudio,
+				audioTracks: [
+					{
+						id: "trk_1",
+						assetId: audioId,
+						timelineStartSec: 0,
+						durationSec: 10,
+						trimStartSec: 0,
+						gainDb: 0,
+						label: "music",
+					},
+				],
+			});
+			expect(withTrack.audioTracks).toHaveLength(1);
+			const after = await service.removeAsset(doc.project.id, audioId);
+			expect(after.audioTracks).toEqual([]);
+			expect(after.assets.some((a) => a.id === audioId)).toBe(false);
+		});
+
 		it("resequences other assets and rederives their anchored regions", async () => {
 			const created = await service.createProject("P");
 			const withA = await service.addAsset(created.project.id, { path: "/tmp/a.mp4" });
diff --git a/electron/ai-edition/document-service.ts b/electron/ai-edition/document-service.ts
index f519379e4..cf471e4df 100644
--- a/electron/ai-edition/document-service.ts
+++ b/electron/ai-edition/document-service.ts
@@ -359,9 +359,13 @@ export class DocumentService {
 			throw new ProjectFileError(`Asset ${assetId} not found in project ${projectId}.`, projectId);
 		}
 		const assets = doc.assets.filter((a) => a.id !== assetId);
+		// Primary is the thing the timeline is built around, so it must fall to the
+		// next VIDEO asset — never an audio overlay (issue #350), which can't be
+		// primary (see addAsset). Falling back to `assets[0]` would hand primary to
+		// an audio asset when the removed one was the last video.
 		const primaryAssetId =
 			doc.project.primaryAssetId === assetId
-				? (assets[0]?.id ?? undefined)
+				? (assets.find((a) => a.kind !== "audio")?.id ?? undefined)
 				: doc.project.primaryAssetId;
 		const withoutAssetClips = doc.timeline.clips
 			.filter((clip) => clip.assetId === assetId)
@@ -369,6 +373,9 @@ export class DocumentService {
 		const next: AxcutDocument = {
 			...withoutAssetClips,
 			assets,
+			// Drop imported audio tracks that referenced the removed asset — they
+			// would otherwise dangle, pointing at an asset the document no longer has.
+			audioTracks: withoutAssetClips.audioTracks.filter((t) => t.assetId !== assetId),
 			timeline: {
 				...withoutAssetClips.timeline,
 				trimRanges: withoutAssetClips.timeline.trimRanges.filter((r) => r.assetId !== assetId),
diff --git a/src/components/ai-edition/v4/V4Timeline.tsx b/src/components/ai-edition/v4/V4Timeline.tsx
index cff3eb60e..a03368963 100644
--- a/src/components/ai-edition/v4/V4Timeline.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.tsx
@@ -933,7 +933,10 @@ export function V4Timeline({
 				let nts = origTrimStart;
 				let nte = origTrimEnd;
 				if (mode === "move") {
-					ns = Math.max(0, snap(origStart + dxSec));
+					// Cap so the whole track lands by `total`: no pill past 100%, and the
+					// export (which truncates at the programme end) matches what's shown.
+					const upper = Math.max(0, total - (origTrimEnd - origTrimStart));
+					ns = Math.min(Math.max(0, snap(origStart + dxSec)), upper);
 				} else if (mode === "l") {
 					// The left edge can't cross the right one, and can't reveal more head
 					// than the source has (trimStart floors at 0 → head floors at
@@ -950,7 +953,12 @@ export function V4Timeline({
 					// position of the edge, then map back to a source out-point.
 					const snappedRight = snap(origStart + (origTrimEnd - origTrimStart) + dxSec);
 					const newTrimEnd = origTrimStart + (snappedRight - origStart);
-					nte = Math.min(Math.max(newTrimEnd, origTrimStart + MIN_REGION_SEC), maxEnd);
+					// Cap the out-point at the source length AND the programme end (`total`).
+					nte = Math.min(
+						Math.max(newTrimEnd, origTrimStart + MIN_REGION_SEC),
+						maxEnd,
+						origTrimStart + Math.max(0, total - origStart),
+					);
 				}
 				const next = { id: track.id, start: ns, trimStart: nts, trimEnd: nte };
 				audioDragRef.current = next;
diff --git a/src/i18n/locales/ar/dialogs.json b/src/i18n/locales/ar/dialogs.json
index 1032d22cb..cf7c6f554 100644
--- a/src/i18n/locales/ar/dialogs.json
+++ b/src/i18n/locales/ar/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "حفظ GIF المصدر",
 		"saveVideo": "حفظ الفيديو المصدر",
 		"selectVideo": "حدد ملف فيديو",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "اختر ملف صوت",
 		"saveProject": "حفظ مشروع OpenScreen",
 		"openProject": "فتح مشروع OpenScreen",
 		"gifImage": "صورة GIF",
 		"mp4Video": "فيديو MP4",
 		"videoFiles": "ملفات فيديو",
-		"audioFiles": "Audio Files",
+		"audioFiles": "ملفات الصوت",
 		"openscreenProject": "مشروع OpenScreen",
 		"allFiles": "جميع الملفات"
 	}
diff --git a/src/i18n/locales/ar/settings.json b/src/i18n/locales/ar/settings.json
index 38dd38a5c..ac794f2bb 100644
--- a/src/i18n/locales/ar/settings.json
+++ b/src/i18n/locales/ar/settings.json
@@ -321,10 +321,10 @@
 		"help": "اضبط مستوى إخراج الصوت. يُطبَّق بالطريقة نفسها في المعاينة وعند التصدير."
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "إضافة مسار صوتي",
+		"importFailed": "تعذّر إضافة الصوت",
+		"defaultLabel": "مسار صوتي",
+		"help": "مستوى صوت هذا المسار الصوتي المستورد. يُمزج فوق التسجيل في المعاينة والتصدير. اسحب المسار على المخطط الزمني لتحريكه أو اقتصاصه.",
+		"remove": "حذف المسار"
 	}
 }
diff --git a/src/i18n/locales/es/dialogs.json b/src/i18n/locales/es/dialogs.json
index 10ebb2315..8f26a3aff 100644
--- a/src/i18n/locales/es/dialogs.json
+++ b/src/i18n/locales/es/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Guardar GIF exportado",
 		"saveVideo": "Guardar video exportado",
 		"selectVideo": "Seleccionar archivo de video",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "Seleccionar archivo de audio",
 		"saveProject": "Guardar proyecto OpenScreen",
 		"openProject": "Abrir proyecto OpenScreen",
 		"gifImage": "Imagen GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "Archivos de video",
-		"audioFiles": "Audio Files",
+		"audioFiles": "Archivos de audio",
 		"openscreenProject": "Proyecto OpenScreen",
 		"allFiles": "Todos los archivos"
 	}
diff --git a/src/i18n/locales/es/settings.json b/src/i18n/locales/es/settings.json
index 2464f3980..15d2dfef0 100644
--- a/src/i18n/locales/es/settings.json
+++ b/src/i18n/locales/es/settings.json
@@ -321,10 +321,10 @@
 		"help": "Ajusta el nivel de salida del audio. Se aplica igual en la vista previa y en la exportación."
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "Añadir pista de audio",
+		"importFailed": "No se pudo añadir el audio",
+		"defaultLabel": "Pista de audio",
+		"help": "Volumen de esta pista de audio importada. Se mezcla sobre la grabación en la vista previa y en la exportación. Arrastra la pista en la línea de tiempo para moverla o recortarla.",
+		"remove": "Eliminar pista"
 	}
 }
diff --git a/src/i18n/locales/fr/dialogs.json b/src/i18n/locales/fr/dialogs.json
index a7691550e..ad5b4edf6 100644
--- a/src/i18n/locales/fr/dialogs.json
+++ b/src/i18n/locales/fr/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Enregistrer le GIF exporté",
 		"saveVideo": "Enregistrer la vidéo exportée",
 		"selectVideo": "Sélectionner un fichier vidéo",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "Sélectionner un fichier audio",
 		"saveProject": "Enregistrer le projet OpenScreen",
 		"openProject": "Ouvrir un projet OpenScreen",
 		"gifImage": "Image GIF",
 		"mp4Video": "Vidéo MP4",
 		"videoFiles": "Fichiers vidéo",
-		"audioFiles": "Audio Files",
+		"audioFiles": "Fichiers audio",
 		"openscreenProject": "Projet OpenScreen",
 		"allFiles": "Tous les fichiers"
 	}
diff --git a/src/i18n/locales/fr/settings.json b/src/i18n/locales/fr/settings.json
index f93a7bd8a..3a5fc92af 100644
--- a/src/i18n/locales/fr/settings.json
+++ b/src/i18n/locales/fr/settings.json
@@ -321,10 +321,10 @@
 		"help": "Ajustez le niveau de sortie audio. Il s’applique à l’identique dans l’aperçu et à l’export."
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "Ajouter une piste audio",
+		"importFailed": "Impossible d’ajouter l’audio",
+		"defaultLabel": "Piste audio",
+		"help": "Volume de cette piste audio importée. Elle est mixée par-dessus l’enregistrement dans l’aperçu et à l’export. Faites glisser la piste sur la timeline pour la déplacer ou la rogner.",
+		"remove": "Supprimer la piste"
 	}
 }
diff --git a/src/i18n/locales/it/dialogs.json b/src/i18n/locales/it/dialogs.json
index b26a83da9..e8e326c91 100644
--- a/src/i18n/locales/it/dialogs.json
+++ b/src/i18n/locales/it/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Salva GIF esportata",
 		"saveVideo": "Salva video esportato",
 		"selectVideo": "Seleziona file video",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "Seleziona file audio",
 		"saveProject": "Salva progetto OpenScreen",
 		"openProject": "Apri progetto OpenScreen",
 		"gifImage": "Immagine GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "File video",
-		"audioFiles": "Audio Files",
+		"audioFiles": "File audio",
 		"openscreenProject": "Progetto OpenScreen",
 		"allFiles": "Tutti i file"
 	}
diff --git a/src/i18n/locales/it/settings.json b/src/i18n/locales/it/settings.json
index f6c9b32e7..5ba1e2c1d 100644
--- a/src/i18n/locales/it/settings.json
+++ b/src/i18n/locales/it/settings.json
@@ -321,10 +321,10 @@
 		"help": "Regola il livello di uscita audio. Si applica allo stesso modo nell’anteprima e nell’esportazione."
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "Aggiungi traccia audio",
+		"importFailed": "Impossibile aggiungere l’audio",
+		"defaultLabel": "Traccia audio",
+		"help": "Volume di questa traccia audio importata. Viene mixata sopra la registrazione nell’anteprima e nell’esportazione. Trascina la traccia sulla timeline per spostarla o ritagliarla.",
+		"remove": "Elimina traccia"
 	}
 }
diff --git a/src/i18n/locales/ja-JP/dialogs.json b/src/i18n/locales/ja-JP/dialogs.json
index 911c2ad94..c0c00ad80 100644
--- a/src/i18n/locales/ja-JP/dialogs.json
+++ b/src/i18n/locales/ja-JP/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "エクスポートしたGIFを保存",
 		"saveVideo": "エクスポートした動画を保存",
 		"selectVideo": "動画ファイルを選択",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "オーディオファイルを選択",
 		"saveProject": "OpenScreen プロジェクトを保存",
 		"openProject": "OpenScreen プロジェクトを開く",
 		"gifImage": "GIF 画像",
 		"mp4Video": "MP4 動画",
 		"videoFiles": "動画ファイル",
-		"audioFiles": "Audio Files",
+		"audioFiles": "オーディオファイル",
 		"openscreenProject": "OpenScreen プロジェクト",
 		"allFiles": "すべてのファイル"
 	}
diff --git a/src/i18n/locales/ja-JP/settings.json b/src/i18n/locales/ja-JP/settings.json
index 91b194c4c..a16b990bd 100644
--- a/src/i18n/locales/ja-JP/settings.json
+++ b/src/i18n/locales/ja-JP/settings.json
@@ -321,10 +321,10 @@
 		"help": "音声の出力レベルを調整します。プレビューと書き出しで同じように適用されます。"
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "オーディオトラックを追加",
+		"importFailed": "オーディオを追加できませんでした",
+		"defaultLabel": "オーディオトラック",
+		"help": "このインポートしたオーディオトラックの音量。プレビューとエクスポートで録画に重ねてミックスされます。タイムライン上でドラッグして移動またはトリミングできます。",
+		"remove": "トラックを削除"
 	}
 }
diff --git a/src/i18n/locales/ko-KR/dialogs.json b/src/i18n/locales/ko-KR/dialogs.json
index d654a5f52..2b64240ae 100644
--- a/src/i18n/locales/ko-KR/dialogs.json
+++ b/src/i18n/locales/ko-KR/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "내보낸 GIF 저장",
 		"saveVideo": "내보낸 비디오 저장",
 		"selectVideo": "비디오 파일 선택",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "오디오 파일 선택",
 		"saveProject": "OpenScreen 프로젝트 저장",
 		"openProject": "OpenScreen 프로젝트 열기",
 		"gifImage": "GIF 이미지",
 		"mp4Video": "MP4 비디오",
 		"videoFiles": "비디오 파일",
-		"audioFiles": "Audio Files",
+		"audioFiles": "오디오 파일",
 		"openscreenProject": "OpenScreen 프로젝트",
 		"allFiles": "모든 파일"
 	}
diff --git a/src/i18n/locales/ko-KR/settings.json b/src/i18n/locales/ko-KR/settings.json
index f0b381f8e..93a97fe76 100644
--- a/src/i18n/locales/ko-KR/settings.json
+++ b/src/i18n/locales/ko-KR/settings.json
@@ -321,10 +321,10 @@
 		"help": "오디오 출력 레벨을 조정합니다. 미리보기와 내보내기에 동일하게 적용됩니다."
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "오디오 트랙 추가",
+		"importFailed": "오디오를 추가할 수 없습니다",
+		"defaultLabel": "오디오 트랙",
+		"help": "가져온 이 오디오 트랙의 볼륨입니다. 미리 보기와 내보내기에서 녹화 위에 믹싱됩니다. 타임라인에서 트랙을 드래그하여 이동하거나 자를 수 있습니다.",
+		"remove": "트랙 삭제"
 	}
 }
diff --git a/src/i18n/locales/pt-BR/dialogs.json b/src/i18n/locales/pt-BR/dialogs.json
index 7dbb4c642..88f163d99 100644
--- a/src/i18n/locales/pt-BR/dialogs.json
+++ b/src/i18n/locales/pt-BR/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Salvar GIF Exportado",
 		"saveVideo": "Salvar Vídeo Exportado",
 		"selectVideo": "Selecionar Arquivo de Vídeo",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "Selecionar arquivo de áudio",
 		"saveProject": "Salvar Projeto OpenScreen",
 		"openProject": "Abrir Projeto OpenScreen",
 		"gifImage": "Imagem GIF",
 		"mp4Video": "Vídeo MP4",
 		"videoFiles": "Arquivos de Vídeo",
-		"audioFiles": "Audio Files",
+		"audioFiles": "Arquivos de áudio",
 		"openscreenProject": "Projeto OpenScreen",
 		"allFiles": "Todos os Arquivos"
 	}
diff --git a/src/i18n/locales/pt-BR/settings.json b/src/i18n/locales/pt-BR/settings.json
index cdfcc39d8..7e18be910 100644
--- a/src/i18n/locales/pt-BR/settings.json
+++ b/src/i18n/locales/pt-BR/settings.json
@@ -321,10 +321,10 @@
 		"help": "Ajuste o nível de saída do áudio. Ele se aplica da mesma forma na prévia e na exportação."
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "Adicionar faixa de áudio",
+		"importFailed": "Não foi possível adicionar o áudio",
+		"defaultLabel": "Faixa de áudio",
+		"help": "Volume desta faixa de áudio importada. Ela é mixada sobre a gravação na prévia e na exportação. Arraste a faixa na linha do tempo para movê-la ou cortá-la.",
+		"remove": "Excluir faixa"
 	}
 }
diff --git a/src/i18n/locales/ru/dialogs.json b/src/i18n/locales/ru/dialogs.json
index 7e1dbaeed..1f46a14fc 100644
--- a/src/i18n/locales/ru/dialogs.json
+++ b/src/i18n/locales/ru/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Сохранить экспортированный GIF",
 		"saveVideo": "Сохранить экспортированное видео",
 		"selectVideo": "Выбрать видеофайл",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "Выбрать аудиофайл",
 		"saveProject": "Сохранить проект OpenScreen",
 		"openProject": "Открыть проект OpenScreen",
 		"gifImage": "GIF изображение",
 		"mp4Video": "MP4 видео",
 		"videoFiles": "Видеофайлы",
-		"audioFiles": "Audio Files",
+		"audioFiles": "Аудиофайлы",
 		"openscreenProject": "Проект OpenScreen",
 		"allFiles": "Все файлы"
 	}
diff --git a/src/i18n/locales/ru/settings.json b/src/i18n/locales/ru/settings.json
index fa11b5061..3a4d042ac 100644
--- a/src/i18n/locales/ru/settings.json
+++ b/src/i18n/locales/ru/settings.json
@@ -321,10 +321,10 @@
 		"help": "Настройте уровень звука на выходе. Он одинаково применяется в предпросмотре и при экспорте."
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "Добавить аудиодорожку",
+		"importFailed": "Не удалось добавить аудио",
+		"defaultLabel": "Аудиодорожка",
+		"help": "Громкость импортированной аудиодорожки. Она микшируется поверх записи в предпросмотре и при экспорте. Перетащите дорожку на шкале времени, чтобы переместить или обрезать её.",
+		"remove": "Удалить дорожку"
 	}
 }
diff --git a/src/i18n/locales/tr/dialogs.json b/src/i18n/locales/tr/dialogs.json
index c6299d520..6b01da744 100644
--- a/src/i18n/locales/tr/dialogs.json
+++ b/src/i18n/locales/tr/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Dışa Aktarılan GIF'i Kaydet",
 		"saveVideo": "Dışa Aktarılan Videoyu Kaydet",
 		"selectVideo": "Video Dosyası Seç",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "Ses dosyası seç",
 		"saveProject": "OpenScreen Projesini Kaydet",
 		"openProject": "OpenScreen Projesini Aç",
 		"gifImage": "GIF Görüntüsü",
 		"mp4Video": "MP4 Video",
 		"videoFiles": "Video Dosyaları",
-		"audioFiles": "Audio Files",
+		"audioFiles": "Ses dosyaları",
 		"openscreenProject": "OpenScreen Projesi",
 		"allFiles": "Tüm Dosyalar"
 	}
diff --git a/src/i18n/locales/tr/settings.json b/src/i18n/locales/tr/settings.json
index 1444cb21a..8d8143fa3 100644
--- a/src/i18n/locales/tr/settings.json
+++ b/src/i18n/locales/tr/settings.json
@@ -321,10 +321,10 @@
 		"help": "Ses çıkış seviyesini ayarlayın. Önizlemede ve dışa aktarmada aynı şekilde uygulanır."
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "Ses parçası ekle",
+		"importFailed": "Ses eklenemedi",
+		"defaultLabel": "Ses parçası",
+		"help": "Bu içe aktarılmış ses parçasının ses düzeyi. Önizlemede ve dışa aktarmada kaydın üzerine miksleniyor. Taşımak veya kırpmak için parçayı zaman çizelgesinde sürükleyin.",
+		"remove": "Parçayı sil"
 	}
 }
diff --git a/src/i18n/locales/vi/dialogs.json b/src/i18n/locales/vi/dialogs.json
index 213240763..452e80e2f 100644
--- a/src/i18n/locales/vi/dialogs.json
+++ b/src/i18n/locales/vi/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "Lưu GIF đã xuất",
 		"saveVideo": "Lưu Video đã xuất",
 		"selectVideo": "Chọn tệp video",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "Chọn tệp âm thanh",
 		"saveProject": "Lưu dự án OpenScreen",
 		"openProject": "Mở dự án OpenScreen",
 		"gifImage": "Hình ảnh GIF",
 		"mp4Video": "Video MP4",
 		"videoFiles": "Tệp Video",
-		"audioFiles": "Audio Files",
+		"audioFiles": "Tệp âm thanh",
 		"openscreenProject": "Dự án OpenScreen",
 		"allFiles": "Tất cả các tệp"
 	}
diff --git a/src/i18n/locales/vi/settings.json b/src/i18n/locales/vi/settings.json
index e6191c8a2..72383cd90 100644
--- a/src/i18n/locales/vi/settings.json
+++ b/src/i18n/locales/vi/settings.json
@@ -321,10 +321,10 @@
 		"help": "Điều chỉnh mức đầu ra của âm thanh. Nó được áp dụng giống hệt nhau trong bản xem trước và khi xuất."
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "Thêm bản âm thanh",
+		"importFailed": "Không thể thêm âm thanh",
+		"defaultLabel": "Bản âm thanh",
+		"help": "Âm lượng của bản âm thanh đã nhập này. Nó được trộn lên trên bản ghi trong bản xem trước và khi xuất. Kéo bản nhạc trên dòng thời gian để di chuyển hoặc cắt.",
+		"remove": "Xóa bản nhạc"
 	}
 }
diff --git a/src/i18n/locales/zh-CN/dialogs.json b/src/i18n/locales/zh-CN/dialogs.json
index b28304f6c..db4f12730 100644
--- a/src/i18n/locales/zh-CN/dialogs.json
+++ b/src/i18n/locales/zh-CN/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "保存导出的 GIF",
 		"saveVideo": "保存导出的视频",
 		"selectVideo": "选择视频文件",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "选择音频文件",
 		"saveProject": "保存 OpenScreen 项目",
 		"openProject": "打开 OpenScreen 项目",
 		"gifImage": "GIF 图片",
 		"mp4Video": "MP4 视频",
 		"videoFiles": "视频文件",
-		"audioFiles": "Audio Files",
+		"audioFiles": "音频文件",
 		"openscreenProject": "OpenScreen 项目",
 		"allFiles": "所有文件"
 	}
diff --git a/src/i18n/locales/zh-CN/settings.json b/src/i18n/locales/zh-CN/settings.json
index 30de68b90..452d41550 100644
--- a/src/i18n/locales/zh-CN/settings.json
+++ b/src/i18n/locales/zh-CN/settings.json
@@ -321,10 +321,10 @@
 		"help": "调整音频输出电平。它在预览和导出中的效果完全一致。"
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "添加音频轨道",
+		"importFailed": "无法添加音频",
+		"defaultLabel": "音频轨道",
+		"help": "此导入音频轨道的音量。在预览和导出中会叠加混合到录制内容上。在时间轴上拖动轨道即可移动或裁剪。",
+		"remove": "删除轨道"
 	}
 }
diff --git a/src/i18n/locales/zh-TW/dialogs.json b/src/i18n/locales/zh-TW/dialogs.json
index 6c3601511..f4830a611 100644
--- a/src/i18n/locales/zh-TW/dialogs.json
+++ b/src/i18n/locales/zh-TW/dialogs.json
@@ -79,13 +79,13 @@
 		"saveGif": "儲存匯出的 GIF",
 		"saveVideo": "儲存匯出的影片",
 		"selectVideo": "選擇影片檔案",
-		"selectAudio": "Select Audio File",
+		"selectAudio": "選擇音訊檔案",
 		"saveProject": "儲存 OpenScreen 專案",
 		"openProject": "開啟 OpenScreen 專案",
 		"gifImage": "GIF 圖片",
 		"mp4Video": "MP4 影片",
 		"videoFiles": "影片檔案",
-		"audioFiles": "Audio Files",
+		"audioFiles": "音訊檔案",
 		"openscreenProject": "OpenScreen 專案",
 		"allFiles": "所有檔案"
 	}
diff --git a/src/i18n/locales/zh-TW/settings.json b/src/i18n/locales/zh-TW/settings.json
index d3a17cb24..a6c599e53 100644
--- a/src/i18n/locales/zh-TW/settings.json
+++ b/src/i18n/locales/zh-TW/settings.json
@@ -322,10 +322,10 @@
 		"help": "調整音訊輸出電平。它在預覽與匯出中的效果完全一致。"
 	},
 	"audioTrack": {
-		"add": "Add audio track",
-		"importFailed": "Could not add audio",
-		"defaultLabel": "Audio track",
-		"help": "Volume, position, and mute for this imported audio track. It mixes over the recording in the preview and the export.",
-		"remove": "Delete track"
+		"add": "新增音訊軌道",
+		"importFailed": "無法新增音訊",
+		"defaultLabel": "音訊軌道",
+		"help": "此匯入音訊軌道的音量。在預覽與匯出時會疊加混音到錄製內容上。在時間軸上拖曳軌道即可移動或裁剪。",
+		"remove": "刪除軌道"
 	}
 }
diff --git a/src/lib/ai-edition/store/documentWriteAudit.test.ts b/src/lib/ai-edition/store/documentWriteAudit.test.ts
index 3641782fb..4647d87a4 100644
--- a/src/lib/ai-edition/store/documentWriteAudit.test.ts
+++ b/src/lib/ai-edition/store/documentWriteAudit.test.ts
@@ -267,6 +267,9 @@ const DECLARED: WritePath[] = [
 	// Source-dimension backfill for assets a migration left unprobed. On load, for
 	// every project, whether or not the user touches anything.
 	w("src/lib/ai-edition/store/useTimeline.ts", "useTimeline", "save", "automatic"),
+	// Audio-duration backfill (issue #350) — the same on-load, un-asked-for probe
+	// for imported audio assets whose duration didn't stamp at import.
+	w("src/lib/ai-edition/store/useTimeline.ts", "useTimeline", "save", "automatic"),
 ];
 
 function w(
diff --git a/src/lib/ai-edition/store/projectStore.test.ts b/src/lib/ai-edition/store/projectStore.test.ts
index e2f69fce7..6039f0a11 100644
--- a/src/lib/ai-edition/store/projectStore.test.ts
+++ b/src/lib/ai-edition/store/projectStore.test.ts
@@ -341,8 +341,7 @@ describe("useProjectStore", () => {
 			"audio",
 		);
 		// Audio has no camera sidecar — the lookup that addAsset does must not run.
-		// biome-ignore lint/suspicious/noExplicitAny: test-only stub of the legacy contextBridge surface
-		expect((window as any).electronAPI.findRecordingCamera).not.toHaveBeenCalled();
+		expect(vi.mocked(window.electronAPI.findRecordingCamera)).not.toHaveBeenCalled();
 		// Probe returned null, so nothing to stamp: no extra save.
 		expect(bridgeMocks.save).not.toHaveBeenCalled();
 	});
diff --git a/src/lib/ai-edition/store/projectStore.ts b/src/lib/ai-edition/store/projectStore.ts
index fef92136e..1b8217753 100644
--- a/src/lib/ai-edition/store/projectStore.ts
+++ b/src/lib/ai-edition/store/projectStore.ts
@@ -426,8 +426,11 @@ export const useProjectStore = create<ProjectState>((set, get) => ({
 		const asset = await get().addAudioAsset(path, label);
 		if (!asset) return null;
 		// addAudioAsset already committed the asset (with its probed duration), so
-		// the current document is the one to place the track on.
-		await get().addAudioTrack(asset.id);
+		// the current document is the one to place the track on. If the placement
+		// write fails or is superseded, the import did NOT succeed as a one-shot —
+		// report failure rather than claim success with an asset but no track.
+		const trackId = await get().addAudioTrack(asset.id);
+		if (!trackId) return null;
 		return asset;
 	},
 
diff --git a/src/lib/ai-edition/store/useTimeline.test.ts b/src/lib/ai-edition/store/useTimeline.test.ts
index c79ec343f..68bf29a97 100644
--- a/src/lib/ai-edition/store/useTimeline.test.ts
+++ b/src/lib/ai-edition/store/useTimeline.test.ts
@@ -20,6 +20,7 @@ const probeVideoDurationMock = vi.hoisted(() => vi.fn());
 const probeVideoDimensionsMock = vi.hoisted(() =>
 	vi.fn().mockResolvedValue({ width: 1920, height: 1080 }),
 );
+const probeAudioDurationMock = vi.hoisted(() => vi.fn().mockResolvedValue(null));
 const toastErrorMock = vi.hoisted(() => vi.fn());
 
 vi.mock("sonner", () => ({ toast: { error: toastErrorMock } }));
@@ -30,6 +31,7 @@ vi.mock("../timeline/duration", async (importOriginal) => {
 		...actual,
 		probeVideoDuration: probeVideoDurationMock,
 		probeVideoDimensions: probeVideoDimensionsMock,
+		probeAudioDuration: probeAudioDurationMock,
 	};
 });
 
@@ -1310,6 +1312,8 @@ describe("useTimeline audio tracks", () => {
 		useProjectStore.getState().clear();
 		clearHistory();
 		for (const mock of Object.values(bridgeMocks)) mock.mockReset();
+		probeAudioDurationMock.mockReset();
+		probeAudioDurationMock.mockResolvedValue(null);
 		bridgeMocks.save.mockImplementation(async (doc: typeof sampleDoc) => ({
 			success: true,
 			document: doc,
@@ -1402,4 +1406,50 @@ describe("useTimeline audio tracks", () => {
 		});
 		expect(useProjectStore.getState().document?.audioTracks).toEqual([]);
 	});
+
+	// #350 regression: a failed import-time probe leaves durationSec at 0, which
+	// makes the playback window zero-length. The on-load backfill re-probes and
+	// stamps the real duration onto the asset AND the track, so it can play again.
+	it("backfills a missing audio duration on load", async () => {
+		probeAudioDurationMock.mockResolvedValue(12.5);
+		// Asset imported with an unknown duration (probe failed), and a track that
+		// cached the resulting 0.
+		useProjectStore.setState({
+			projectId: "proj_test",
+			document: {
+				...sampleDoc,
+				assets: [
+					...sampleDoc.assets,
+					{
+						id: "audio_2",
+						kind: "audio",
+						label: "bgm.mp3",
+						originalPath: "/tmp/bgm.mp3",
+						cameraTrack: null,
+					},
+				],
+				audioTracks: [
+					{
+						id: "trk_2",
+						assetId: "audio_2",
+						timelineStartSec: 0,
+						durationSec: 0,
+						trimStartSec: 0,
+						gainDb: 0,
+						label: "bgm.mp3",
+					},
+				],
+			},
+			revision: 1,
+			status: "ready",
+			error: null,
+		});
+		renderTimeline();
+		await waitFor(() => {
+			const doc = useProjectStore.getState().document;
+			expect(doc?.assets.find((a) => a.id === "audio_2")?.durationSec).toBe(12.5);
+			expect(doc?.audioTracks[0]?.durationSec).toBe(12.5);
+		});
+		expect(probeAudioDurationMock).toHaveBeenCalledTimes(1);
+	});
 });
diff --git a/src/lib/ai-edition/store/useTimeline.ts b/src/lib/ai-edition/store/useTimeline.ts
index aed880208..df761bfed 100644
--- a/src/lib/ai-edition/store/useTimeline.ts
+++ b/src/lib/ai-edition/store/useTimeline.ts
@@ -26,7 +26,7 @@ import {
 } from "../document/timeline";
 import type { AxcutClipCropRegion, AxcutDocument } from "../schema";
 import { hasAnyClipWithCamera } from "../timeline/camera";
-import { probeVideoDimensions, probeVideoDuration } from "../timeline/duration";
+import { probeAudioDuration, probeVideoDimensions, probeVideoDuration } from "../timeline/duration";
 import {
 	anchorRegionsWithDerivedMs,
 	dropPillsByIds,
@@ -226,6 +226,57 @@ export function useTimeline() {
 		};
 	}, [document]);
 
+	// Backfill the real duration of imported audio assets (issue #350), the audio
+	// counterpart of the dimension backfill above. `addAudioAsset` probes once at
+	// import; a transient failure (timeout, a file still being written) would
+	// otherwise leave `durationSec` at 0 forever, and a 0-length window is a track
+	// that never plays and a pill with no width. Re-probe on load — once per asset
+	// per session, success or not — and stamp both the asset AND every track that
+	// caches its duration, with `history: false` so the fix is not an undo step.
+	const probedAudioAssetIdsRef = useRef<Set<string>>(new Set());
+	useEffect(() => {
+		if (!document) return;
+		const usedAssetIds = new Set(document.audioTracks.map((t) => t.assetId));
+		const missing = document.assets.filter(
+			(a) =>
+				a.kind === "audio" &&
+				a.originalPath &&
+				usedAssetIds.has(a.id) &&
+				!(a.durationSec && a.durationSec > 0) &&
+				!probedAudioAssetIdsRef.current.has(a.id),
+		);
+		if (missing.length === 0) return;
+		let cancelled = false;
+		void (async () => {
+			const probed: Record<string, number> = {};
+			for (const a of missing) {
+				probedAudioAssetIdsRef.current.add(a.id);
+				const durationSec = await probeAudioDuration(toFileUrl(a.originalPath));
+				if (durationSec != null && durationSec > 0) probed[a.id] = durationSec;
+			}
+			if (cancelled || Object.keys(probed).length === 0) return;
+			const current = useProjectStore.getState().document;
+			if (!current) return;
+			await useProjectStore.getState().saveDocument(
+				{
+					...current,
+					assets: current.assets.map((a) =>
+						probed[a.id] ? { ...a, durationSec: probed[a.id] } : a,
+					),
+					audioTracks: current.audioTracks.map((t) =>
+						probed[t.assetId] && !(t.durationSec > 0)
+							? { ...t, durationSec: probed[t.assetId] }
+							: t,
+					),
+				},
+				{ history: false },
+			);
+		})();
+		return () => {
+			cancelled = true;
+		};
+	}, [document]);
+
 	// Every add* below anchors the new region to the clip(s) it covers before storing it.
 	// A modifier MUST own a clip anchor to survive reorder/trim (see
 	// technical-documentation/architecture/timeline-model.md) — writing only startMs/endMs
@@ -1209,18 +1260,31 @@ export function useTimeline() {
 
 	// Place a new track for an imported audio asset, its head at the playhead (in
 	// output-timeline seconds) unless the caller says otherwise. Delegates to the
-	// store op, which also selects the new track and returns its id (or null).
+	// store op, which also selects the new track and returns its id (or null). On
+	// success, retire the hook-local region/clip selection so the new audio-track
+	// selection isn't held CONCURRENTLY with a stale region/clip one.
 	const addAudioTrack = useCallback(
-		(assetId: string, timelineStartSec?: number): Promise<string | null> =>
-			storeAddAudioTrack(assetId, timelineStartSec ?? playheadSec()),
+		async (assetId: string, timelineStartSec?: number): Promise<string | null> => {
+			const id = await storeAddAudioTrack(assetId, timelineStartSec ?? playheadSec());
+			if (id) {
+				setSelection(null);
+				setMultiSelection([]);
+				setClipSelection(null);
+			}
+			return id;
+		},
 		[storeAddAudioTrack],
 	);
 
 	const removeAudioTrack = useCallback(
 		async (trackId: string) => {
 			if (!document) return;
-			if (selectedAudioTrackId === trackId) setSelectedAudioTrackId(null);
-			await saveDocument(removeAudioTrackInDocument(document, trackId), { history: true });
+			// Clear the inspector selection only AFTER the delete commits. A failed
+			// write leaves the track in the document, so it must keep its selection.
+			const ok = await saveDocument(removeAudioTrackInDocument(document, trackId), {
+				history: true,
+			});
+			if (ok && selectedAudioTrackId === trackId) setSelectedAudioTrackId(null);
 		},
 		[document, saveDocument, selectedAudioTrackId, setSelectedAudioTrackId],
 	);
diff --git a/src/native/browserShim.test.ts b/src/native/browserShim.test.ts
new file mode 100644
index 000000000..07f5966b8
--- /dev/null
+++ b/src/native/browserShim.test.ts
@@ -0,0 +1,60 @@
+// @vitest-environment jsdom
+// The shim persists projects to localStorage, so this needs a DOM.
+import { beforeAll, beforeEach, describe, expect, it } from "vitest";
+import type { AxcutDocument } from "@/lib/ai-edition/schema";
+import { installBrowserShims } from "./browserShim";
+import { nativeBridgeClient } from "./client";
+
+// The bridge contract types `document` as `unknown`; the shim returns real
+// AxcutDocuments, so narrow here rather than reaching for `any`.
+const asDoc = (d: unknown) => d as AxcutDocument;
+
+// installBrowserShims patches the real nativeBridgeClient's methods in place, so
+// installing once is enough; each test starts from a clean localStorage. The
+// `?browser` query is what flips detectBrowserMode() on outside Electron.
+beforeAll(() => {
+	window.history.replaceState(null, "", "/?browser");
+	installBrowserShims();
+});
+beforeEach(() => {
+	localStorage.clear();
+});
+
+async function freshProjectId(): Promise<string> {
+	const created = await nativeBridgeClient.aiEdition.create("P");
+	const id = asDoc(created.document).project.id;
+	if (!id) throw new Error("shim create returned no project");
+	return id;
+}
+
+describe("browserShim addAsset (issue #350)", () => {
+	it("keeps kind 'audio' and does not claim the empty primary slot", async () => {
+		const projectId = await freshProjectId();
+		const res = await nativeBridgeClient.aiEdition.addAsset(
+			projectId,
+			"/tmp/music.mp3",
+			"music",
+			"audio",
+		);
+		const doc = asDoc(res.document);
+		const asset = doc.assets.at(-1);
+		expect(asset?.kind).toBe("audio");
+		// An audio import must never become the primary asset (mirrors the main
+		// process's document-service.addAsset).
+		expect(doc.project.primaryAssetId).toBeUndefined();
+	});
+
+	it("still lets a video import claim the empty primary slot", async () => {
+		const projectId = await freshProjectId();
+		const res = await nativeBridgeClient.aiEdition.addAsset(
+			projectId,
+			"/tmp/screen.mp4",
+			"screen",
+			"video",
+		);
+		const doc = asDoc(res.document);
+		const asset = doc.assets.at(-1);
+		expect(asset?.kind).toBe("video");
+		expect(doc.project.primaryAssetId).toBe(asset?.id);
+	});
+});

From f5339a292f414a9915f8ccd27a149728d1f1899f Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 18:28:53 +0200
Subject: [PATCH 18/20] feat(editor): honor imported-track boost in the preview
 (CodeRabbit #5)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

`element.volume` is spec-clamped to [0, 1], so a track pushed above 0 dB
played at unity in the preview while the export mixed it at full boost —
the preview under-represented exactly the tracks a user deliberately turned
up. Route each mounted track element through its own WebAudio gain node
(source → trackGain → the existing output gain → destination), the same
node type the primary/supplemental sum already uses to boost past 0 dB. The
rAF sets each track's gain live, so a slider drag is picked up without
rebuilding the graph; the effect re-routes only on a real mount/unmount
(keyed on the resolved-track set, not the gains). The `.volume` path stays
as the fallback for when WebAudio is unavailable (jsdom, a denied audio
policy), where a boost still caps — audible, just not amplified.

Effective level is trackGain × outputGain, matching the exporter's order
(mix_external_tracks applies the track gain, finish_audio the output gain).

Adds a preview test that stubs AudioContext and proves a +6.0206 dB track
(×2) drives its gain node to 2 rather than clamping element.volume to 1.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 .../VirtualPreview.playback.test.tsx          | 73 +++++++++++++++++++
 src/components/ai-edition/VirtualPreview.tsx  | 71 ++++++++++++++++--
 2 files changed, 137 insertions(+), 7 deletions(-)

diff --git a/src/components/ai-edition/VirtualPreview.playback.test.tsx b/src/components/ai-edition/VirtualPreview.playback.test.tsx
index ae195532f..13d5121cb 100644
--- a/src/components/ai-edition/VirtualPreview.playback.test.tsx
+++ b/src/components/ai-edition/VirtualPreview.playback.test.tsx
@@ -295,3 +295,76 @@ describe("VirtualPreview imported audio tracks", () => {
 		expect(audioEl.pause).toHaveBeenCalled();
 	});
 });
+
+// Issue #350 — a track boosted past 0 dB must sound boosted in the preview too, not just
+// in the export. `element.volume` caps at 1, so the boost has to ride a WebAudio gain node.
+// jsdom has no WebAudio, so install a minimal fake context and watch the nodes it mints.
+class FakeAudioNode {
+	connect = vi.fn();
+	disconnect = vi.fn();
+}
+class FakeGainNode extends FakeAudioNode {
+	gain = { value: 1 };
+}
+let createdGains: FakeGainNode[] = [];
+class FakeAudioContext {
+	state = "running";
+	destination = new FakeAudioNode();
+	resume = vi.fn(() => Promise.resolve());
+	close = vi.fn(() => Promise.resolve());
+	createMediaElementSource = vi.fn(() => new FakeAudioNode());
+	createGain = vi.fn(() => {
+		const node = new FakeGainNode();
+		createdGains.push(node);
+		return node;
+	});
+}
+
+describe("VirtualPreview imported audio track boost", () => {
+	beforeEach(() => {
+		createdGains = [];
+		vi.stubGlobal("AudioContext", FakeAudioContext);
+	});
+
+	// +6.0206 dB is exactly ×2 in linear gain — a boost `element.volume` (max 1) could never
+	// reach. The graph mints the output gain first, then one gain per track, so the track's
+	// node is the last one created.
+	const boosted = {
+		id: "trk",
+		assetId: "aud",
+		timelineStartSec: 2,
+		durationSec: 10,
+		trimStartSec: 1,
+		trimEndSec: 3,
+		gainDb: 6.0206,
+		label: "",
+	};
+
+	it("drives a per-track gain node past unity instead of capping element.volume", () => {
+		const sources: VideoSource[] = [{ id: "a1", src: "file:///tmp/a1.mp4", label: "a1" }];
+		const audioSources: VideoSource[] = [{ id: "aud", src: "file:///tmp/vo.mp3", label: "vo" }];
+		const { container } = render(
+			<VirtualPreview
+				videoSources={sources}
+				audioTracks={[boosted]}
+				audioSources={audioSources}
+				clips={[clip("c1", "a1", 0, 10, 0)]}
+				onTimeChange={vi.fn()}
+			/>,
+		);
+		const videoEl = container.querySelector("video");
+		if (!videoEl) throw new Error("no <video>");
+		driveVideo(videoEl as HTMLVideoElement);
+		act(() => fireEvent.loadedMetadata(videoEl));
+		const audioEl = container.querySelector<HTMLAudioElement>(
+			'[data-testid="preview-audio-track-trk"]',
+		);
+		if (!audioEl) throw new Error("no track <audio>");
+		driveAudioEl(audioEl);
+
+		tick(); // let the rAF stamp the live gain onto the node
+		const trackGain = createdGains.at(-1);
+		expect(trackGain?.gain.value).toBeCloseTo(2, 3); // boosted, NOT clamped to 1
+		expect(audioEl.volume).toBe(1); // volume left at unity so it doesn't double-attenuate
+	});
+});
diff --git a/src/components/ai-edition/VirtualPreview.tsx b/src/components/ai-edition/VirtualPreview.tsx
index 00b17bc0e..44bb0fd69 100644
--- a/src/components/ai-edition/VirtualPreview.tsx
+++ b/src/components/ai-edition/VirtualPreview.tsx
@@ -244,6 +244,11 @@ export function VirtualPreview({
 	const audioContextRef = useRef<AudioContext | null>(null);
 	const audioContextCloseTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
 	const audioSourceNodesRef = useRef(new WeakMap<HTMLAudioElement, MediaElementAudioSourceNode>());
+	// Per-track gain nodes for imported audio (issue #350). Keyed by track id so the rAF
+	// can set each track's level live (a boost past 0 dB, which `element.volume` can't do —
+	// same reason the primary/supplemental sum through a gain node). The graph effect owns
+	// their lifecycle; the map is cleared and rebuilt whenever the routing is torn down.
+	const audioTrackGainNodesRef = useRef<Map<string, GainNode>>(new Map());
 	const audioGraphRef = useRef<PreviewAudioGraph | null>(null);
 	const videoFrameRef = useRef<HTMLDivElement | null>(null);
 
@@ -310,10 +315,21 @@ export function VirtualPreview({
 		};
 	}, [activeSource?.filePath]);
 
+	// Which imported-track elements are actually mounted (a track is rendered only once its
+	// asset URL resolves — see the JSX). Re-routing the graph is keyed on this set, NOT on the
+	// tracks' gains: a level change is applied live on the existing node by the rAF, so it must
+	// not tear the graph down. Joined ids change only on a real mount/unmount.
+	const mountedAudioTrackKey = audioTracks
+		.filter((track) => audioSources.some((source) => source.id === track.assetId))
+		.map((track) => track.id)
+		.join(",");
+
 	// Sum the audio elements into one gain node so the output trim can boost past 0 dB,
 	// which `element.volume` cannot do. The primary media element carries track 1; on macOS
 	// the existing IPC helper extracts track 2 (normally the microphone) so both are audible
-	// instead of Chromium silently choosing one.
+	// instead of Chromium silently choosing one. Imported tracks (issue #350) join the same
+	// graph through a per-track gain node so their boost survives the preview too.
+	// biome-ignore lint/correctness/useExhaustiveDependencies: mountedAudioTrackKey is the trigger for re-routing tracks; the elements are read from the ref.
 	useEffect(() => {
 		if (!primaryAudioEl || !audioProbeComplete) return;
 		if (supplementalAudioSrc && !supplementalAudioEl) return;
@@ -360,14 +376,48 @@ export function VirtualPreview({
 				// preview outright rather than degrade it.
 			}
 		}
+		// Imported tracks (issue #350): each mounted element gets source → per-track gain →
+		// the output gain, so the effective level is trackGain × outputGain — the same order
+		// the exporter mixes in (mix_external_tracks applies the track gain, finish_audio the
+		// output gain). The rAF sets each node's value; created here at unity as a safe default.
+		const trackGainNodes: GainNode[] = [];
+		audioTrackGainNodesRef.current = new Map();
+		for (const [trackId, element] of audioTrackElsRef.current) {
+			try {
+				let source = audioSourceNodesRef.current.get(element);
+				if (!source) {
+					source = graph.context.createMediaElementSource(element);
+					audioSourceNodesRef.current.set(element, source);
+				}
+				source.disconnect();
+				const trackGain = graph.context.createGain();
+				source.connect(trackGain);
+				trackGain.connect(graph.gain);
+				audioTrackGainNodesRef.current.set(trackId, trackGain);
+				connectedSources.push(source);
+				trackGainNodes.push(trackGain);
+			} catch {
+				// Same rationale as the primary/supplemental loop: routing THIS track failed, so
+				// leave the rest connected. The rAF falls back to `element.volume` for a track
+				// with no gain node (capped at 0 dB, but audible).
+			}
+		}
 		audioGraphRef.current = graph;
 		applyPreviewAudioSettings(graph, elements, audioGainDbRef.current);
 		return () => {
 			audioGraphRef.current = null;
 			for (const source of connectedSources) source.disconnect();
+			for (const trackGain of trackGainNodes) trackGain.disconnect();
+			audioTrackGainNodesRef.current = new Map();
 			graph.gain.disconnect();
 		};
-	}, [primaryAudioEl, supplementalAudioEl, supplementalAudioSrc, audioProbeComplete]);
+	}, [
+		primaryAudioEl,
+		supplementalAudioEl,
+		supplementalAudioSrc,
+		audioProbeComplete,
+		mountedAudioTrackKey,
+	]);
 
 	// Keep one AudioContext for the component. Closing and recreating it on an effect rerun
 	// permanently silences an HTMLAudioElement because createMediaElementSource may only be
@@ -390,6 +440,7 @@ export function VirtualPreview({
 				const context = audioContextRef.current;
 				audioContextRef.current = null;
 				audioSourceNodesRef.current = new WeakMap();
+				audioTrackGainNodesRef.current = new Map();
 				if (context) void context.close();
 			}, 0);
 		};
@@ -522,17 +573,23 @@ export function VirtualPreview({
 			}
 			// Imported audio tracks (issue #350): position each against the RAW
 			// virtual timeline it was placed on, play it only inside its window, and
-			// set its level from the track gain × the global output gain. Using
-			// `.volume` rather than a WebAudio node keeps the delicate
-			// primary/supplemental graph untouched; a boost past 0 dB clamps in the
-			// preview (volume maxes at 1) but is still written to the export.
+			// set its level from the track gain. When the WebAudio graph is up the level
+			// rides a per-track gain node (which CAN boost past 0 dB, and the output node
+			// applies the global gain on top, matching the export); the `.volume` path is
+			// the fallback for when the graph is unavailable — there a boost caps at 0 dB.
 			const globalGain = audioGainScalar(audioGainDbRef.current);
 			for (const track of audioTracksRef.current) {
 				const el = audioTrackElsRef.current.get(track.id);
 				if (!el) continue;
 				const trackTarget = resolveTimelineAudioPlayback(virtualTimeSecRef.current, track);
 				if (el.playbackRate !== v.playbackRate) el.playbackRate = v.playbackRate;
-				el.volume = Math.min(1, audioGainScalar(track.gainDb) * globalGain);
+				const trackGainNode = audioTrackGainNodesRef.current.get(track.id);
+				if (trackGainNode) {
+					trackGainNode.gain.value = audioGainScalar(track.gainDb);
+					if (el.volume !== 1) el.volume = 1;
+				} else {
+					el.volume = Math.min(1, audioGainScalar(track.gainDb) * globalGain);
+				}
 				// Only re-seek on a real discontinuity (a scrub, a trim jump, a first
 				// play), NOT on the sub-frame drift of normal playback. The primary audio
 				// can afford a 25 ms leash because it syncs to the <video>'s own

From 93ae2adaeda2d4222760ab028d0ddedcafe69178 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 18:47:30 +0200
Subject: [PATCH 19/20] feat(editor): always show the audio lane + an "Add
 audio" shortcut (M)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The audio lane was the only timeline lane hidden until it had content, on
the premise (in a now-stale comment) that audio is imported from the media
panel "not a keystroke". Audio is a toolbar peer of the region tools now, so
give it what they have: the lane always renders and, when empty, advertises
the shortcut that fills it ("Press M to add audio") — exactly like the zoom,
trim, annotation, speed, and camera lanes.

Register `addAudio` on M (a free, mnemonic key) in the shortcut config so it
shows in the Shortcuts dialog and is user-rebindable, and handle it in the
editor shell. Unlike its neighbours it opens a file picker rather than
dropping a sized region at the playhead, so it takes no duration.

Lift the picker→import flow out of the timeline toolbar into
`useTimeline.addAudio` so the button and the shortcut share one path; the
toolbar button now calls `tl.addAudio()`.

i18n: add pressAudio / actions.addAudio across all 13 locales.
Tests: addAudio wiring (picker → import, cancel → no-op); shortcut-label
parity still holds.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 src/components/ai-edition/NewEditorShell.tsx |  7 +++
 src/components/ai-edition/v4/V4Timeline.tsx  | 46 ++++++++------------
 src/i18n/locales/ar/shortcuts.json           |  1 +
 src/i18n/locales/ar/timeline.json            |  1 +
 src/i18n/locales/en/shortcuts.json           |  1 +
 src/i18n/locales/en/timeline.json            |  1 +
 src/i18n/locales/es/shortcuts.json           |  1 +
 src/i18n/locales/es/timeline.json            |  1 +
 src/i18n/locales/fr/shortcuts.json           |  1 +
 src/i18n/locales/fr/timeline.json            |  1 +
 src/i18n/locales/it/shortcuts.json           |  1 +
 src/i18n/locales/it/timeline.json            |  1 +
 src/i18n/locales/ja-JP/shortcuts.json        |  1 +
 src/i18n/locales/ja-JP/timeline.json         |  1 +
 src/i18n/locales/ko-KR/shortcuts.json        |  1 +
 src/i18n/locales/ko-KR/timeline.json         |  1 +
 src/i18n/locales/pt-BR/shortcuts.json        |  1 +
 src/i18n/locales/pt-BR/timeline.json         |  1 +
 src/i18n/locales/ru/shortcuts.json           |  1 +
 src/i18n/locales/ru/timeline.json            |  1 +
 src/i18n/locales/tr/shortcuts.json           |  1 +
 src/i18n/locales/tr/timeline.json            |  1 +
 src/i18n/locales/vi/shortcuts.json           |  1 +
 src/i18n/locales/vi/timeline.json            |  1 +
 src/i18n/locales/zh-CN/shortcuts.json        |  1 +
 src/i18n/locales/zh-CN/timeline.json         |  1 +
 src/i18n/locales/zh-TW/shortcuts.json        |  1 +
 src/i18n/locales/zh-TW/timeline.json         |  1 +
 src/lib/ai-edition/store/useTimeline.test.ts | 28 ++++++++++++
 src/lib/ai-edition/store/useTimeline.ts      | 20 +++++++++
 src/lib/shortcuts.ts                         |  3 ++
 31 files changed, 102 insertions(+), 28 deletions(-)

diff --git a/src/components/ai-edition/NewEditorShell.tsx b/src/components/ai-edition/NewEditorShell.tsx
index 2810bdaa3..a56f3f143 100644
--- a/src/components/ai-edition/NewEditorShell.tsx
+++ b/src/components/ai-edition/NewEditorShell.tsx
@@ -1041,6 +1041,13 @@ export function NewEditorShell() {
 				void tl.addAnnotation(newRegionDurationSec());
 				return;
 			}
+			// Unlike its neighbours this opens a file picker rather than dropping a region at
+			// the playhead — there is nothing to size, so it takes no duration (issue #350).
+			if (matchesShortcut(e, shortcuts.addAudio, isMac)) {
+				e.preventDefault();
+				void tl.addAudio();
+				return;
+			}
 			if (matchesShortcut(e, shortcuts.addSpeed, isMac)) {
 				e.preventDefault();
 				void tl.addSpeed(newRegionDurationSec());
diff --git a/src/components/ai-edition/v4/V4Timeline.tsx b/src/components/ai-edition/v4/V4Timeline.tsx
index a03368963..445c0ac51 100644
--- a/src/components/ai-edition/v4/V4Timeline.tsx
+++ b/src/components/ai-edition/v4/V4Timeline.tsx
@@ -485,24 +485,6 @@ export function V4Timeline({
 		shiftPx: number;
 	} | null>(null);
 	const { settings, set: setSettings } = useEditorSettings();
-	const importAudioAsset = useProjectStore((s) => s.importAudioAsset);
-
-	// Import an audio file straight onto the timeline (issue #350). Audio is a
-	// timeline overlay like an annotation, not a media-tab clip, so it is added
-	// from here: pick a file, then `importAudioAsset` adds a kind:"audio" asset and
-	// places a track at the playhead in one step.
-	const handleAddAudio = useCallback(async () => {
-		const picker = await window.electronAPI?.openAudioFilePicker?.();
-		if (!picker?.success || !picker.path) return;
-		try {
-			const label = picker.name || picker.path.split(/[\\/]/).pop() || "Audio";
-			await importAudioAsset(picker.path, label);
-		} catch (err) {
-			toast.error(ts("audioTrack.importFailed"), {
-				description: err instanceof Error ? err.message : String(err),
-			});
-		}
-	}, [importAudioAsset, ts]);
 
 	const [autoEnhanceOpen, setAutoEnhanceOpen] = useState(false);
 	const [autoBusy, setAutoBusy] = useState(false);
@@ -1568,7 +1550,7 @@ export function V4Timeline({
 										className={styles.tlToolBtn}
 										title={ts("audioTrack.add")}
 										aria-label={ts("audioTrack.add")}
-										onClick={() => void handleAddAudio()}
+										onClick={() => void tl.addAudio()}
 									>
 										<Music size={15} />
 									</button>
@@ -1709,12 +1691,20 @@ export function V4Timeline({
 										hasAnyCamera ? t("hints.pressCameraFullscreen") : ts("layout.noWebcam"),
 									)}
 								</div>
-								{/* Imported audio tracks (issue #350). Only shown once a track exists —
-								    audio arrives via the media panel's "Import audio", not a keystroke,
-								    so an empty lane would advertise nothing. */}
-								{tl.audioTracks.length > 0 ? (
-									<div className={`${styles.tlLane} ${styles.tlLaneAudio}`}>
-										{tl.audioTracks.map((track) => {
+								{/* Imported audio tracks (issue #350). Always shown, like every other
+								    lane — "Add audio" is a toolbar peer of the region tools now (and
+								    has a keyboard shortcut), so an empty lane advertises the shortcut
+								    that fills it rather than hiding until the first import. */}
+								<div className={`${styles.tlLane} ${styles.tlLaneAudio}`}>
+									{tl.audioTracks.length === 0 ? (
+										<span
+											className={styles.laneEmpty}
+											style={{ left: `${nav.start * 100}%`, width: `${navSpan * 100}%` }}
+										>
+											{t("hints.pressAudio")}
+										</span>
+									) : (
+										tl.audioTracks.map((track) => {
 											const asset = tl.assets.find((a) => a.id === track.assetId);
 											const duration = asset?.durationSec ?? track.durationSec;
 											// While this track is being dragged, lay it out from the live
@@ -1738,9 +1728,9 @@ export function V4Timeline({
 													label={track.label || asset?.label || ts("audioTrack.defaultLabel")}
 												/>
 											);
-										})}
-									</div>
-								) : null}
+										})
+									)}
+								</div>
 							</>
 						) : null}
 
diff --git a/src/i18n/locales/ar/shortcuts.json b/src/i18n/locales/ar/shortcuts.json
index d8c063784..f9a834289 100644
--- a/src/i18n/locales/ar/shortcuts.json
+++ b/src/i18n/locales/ar/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "إضافة قص",
 		"addSpeed": "إضافة سرعة",
 		"addAnnotation": "إضافة شرح",
+		"addAudio": "إضافة صوت",
 		"addKeyframe": "إضافة إطار رئيسي",
 		"addCameraFullscreen": "إضافة كاميرا كاملة الشاشة",
 		"deleteSelected": "حذف المحدد",
diff --git a/src/i18n/locales/ar/timeline.json b/src/i18n/locales/ar/timeline.json
index 4412a0a0b..598e9e625 100644
--- a/src/i18n/locales/ar/timeline.json
+++ b/src/i18n/locales/ar/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "اضغط Z لإضافة تكبير",
 		"pressTrim": "اضغط T لإضافة قص",
 		"pressAnnotation": "اضغط A لإضافة شرح",
+		"pressAudio": "اضغط M لإضافة صوت",
 		"pressSpeed": "اضغط S لإضافة سرعة",
 		"pressCameraFullscreen": "اضغط C لإضافة مقطع كاميرا كاملة الشاشة"
 	},
diff --git a/src/i18n/locales/en/shortcuts.json b/src/i18n/locales/en/shortcuts.json
index 081aceada..ab4e9e45d 100644
--- a/src/i18n/locales/en/shortcuts.json
+++ b/src/i18n/locales/en/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "Add Trim",
 		"addSpeed": "Add Speed",
 		"addAnnotation": "Add Annotation",
+		"addAudio": "Add Audio",
 		"addKeyframe": "Add Keyframe",
 		"addCameraFullscreen": "Add Full Camera",
 		"deleteSelected": "Delete Selected",
diff --git a/src/i18n/locales/en/timeline.json b/src/i18n/locales/en/timeline.json
index c41966115..d5e11e7e2 100644
--- a/src/i18n/locales/en/timeline.json
+++ b/src/i18n/locales/en/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "Press Z to add zoom",
 		"pressTrim": "Press T to add trim",
 		"pressAnnotation": "Press A to add annotation",
+		"pressAudio": "Press M to add audio",
 		"pressSpeed": "Press S to add speed",
 		"pressCameraFullscreen": "Press C to add a Full Camera segment"
 	},
diff --git a/src/i18n/locales/es/shortcuts.json b/src/i18n/locales/es/shortcuts.json
index 970c52306..7753389d2 100644
--- a/src/i18n/locales/es/shortcuts.json
+++ b/src/i18n/locales/es/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "Agregar recorte",
 		"addSpeed": "Agregar velocidad",
 		"addAnnotation": "Agregar anotación",
+		"addAudio": "Añadir audio",
 		"addKeyframe": "Agregar fotograma clave",
 		"addCameraFullscreen": "Agregar cámara a pantalla completa",
 		"deleteSelected": "Eliminar seleccionado",
diff --git a/src/i18n/locales/es/timeline.json b/src/i18n/locales/es/timeline.json
index 989289e00..2c2e64f4f 100644
--- a/src/i18n/locales/es/timeline.json
+++ b/src/i18n/locales/es/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "Presiona Z para agregar zoom",
 		"pressTrim": "Presiona T para agregar recorte",
 		"pressAnnotation": "Presiona A para agregar anotación",
+		"pressAudio": "Pulsa M para añadir audio",
 		"pressSpeed": "Presiona S para agregar velocidad",
 		"pressCameraFullscreen": "Presiona C para agregar un segmento de cámara a pantalla completa"
 	},
diff --git a/src/i18n/locales/fr/shortcuts.json b/src/i18n/locales/fr/shortcuts.json
index 659ef13b8..93ff5af11 100644
--- a/src/i18n/locales/fr/shortcuts.json
+++ b/src/i18n/locales/fr/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "Ajouter une coupe",
 		"addSpeed": "Ajouter une vitesse",
 		"addAnnotation": "Ajouter une annotation",
+		"addAudio": "Ajouter un audio",
 		"addKeyframe": "Ajouter une image-clé",
 		"addCameraFullscreen": "Ajouter une caméra en plein écran",
 		"deleteSelected": "Supprimer la sélection",
diff --git a/src/i18n/locales/fr/timeline.json b/src/i18n/locales/fr/timeline.json
index a35b8858a..aef72afba 100644
--- a/src/i18n/locales/fr/timeline.json
+++ b/src/i18n/locales/fr/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "Appuyez sur Z pour ajouter un zoom",
 		"pressTrim": "Appuyez sur T pour ajouter une coupe",
 		"pressAnnotation": "Appuyez sur A pour ajouter une annotation",
+		"pressAudio": "Appuyez sur M pour ajouter un audio",
 		"pressSpeed": "Appuyez sur S pour ajouter une vitesse",
 		"pressCameraFullscreen": "Appuyez sur C pour ajouter un segment Caméra plein écran"
 	},
diff --git a/src/i18n/locales/it/shortcuts.json b/src/i18n/locales/it/shortcuts.json
index 6a2da2208..5e7eeee42 100644
--- a/src/i18n/locales/it/shortcuts.json
+++ b/src/i18n/locales/it/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "Aggiungi taglio",
 		"addSpeed": "Aggiungi velocità",
 		"addAnnotation": "Aggiungi annotazione",
+		"addAudio": "Aggiungi audio",
 		"addKeyframe": "Aggiungi fotogramma chiave",
 		"addCameraFullscreen": "Aggiungi Camera a schermo intero",
 		"deleteSelected": "Elimina selezionato",
diff --git a/src/i18n/locales/it/timeline.json b/src/i18n/locales/it/timeline.json
index 09bb116ee..1fe62947d 100644
--- a/src/i18n/locales/it/timeline.json
+++ b/src/i18n/locales/it/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "Premi Z per aggiungere zoom",
 		"pressTrim": "Premi T per aggiungere taglio",
 		"pressAnnotation": "Premi A per aggiungere annotazione",
+		"pressAudio": "Premi M per aggiungere audio",
 		"pressSpeed": "Premi S per aggiungere velocità",
 		"pressCameraFullscreen": "Premi C per aggiungere un segmento Camera a schermo intero"
 	},
diff --git a/src/i18n/locales/ja-JP/shortcuts.json b/src/i18n/locales/ja-JP/shortcuts.json
index 173355c66..1d994fb68 100644
--- a/src/i18n/locales/ja-JP/shortcuts.json
+++ b/src/i18n/locales/ja-JP/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "トリムを追加",
 		"addSpeed": "速度を追加",
 		"addAnnotation": "注釈を追加",
+		"addAudio": "音声を追加",
 		"addKeyframe": "キーフレームを追加",
 		"addCameraFullscreen": "フルスクリーンカメラを追加",
 		"deleteSelected": "選択を削除",
diff --git a/src/i18n/locales/ja-JP/timeline.json b/src/i18n/locales/ja-JP/timeline.json
index 68911ba91..7a5f983d8 100644
--- a/src/i18n/locales/ja-JP/timeline.json
+++ b/src/i18n/locales/ja-JP/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "Zキーを押してズームを追加",
 		"pressTrim": "Tキーを押してトリムを追加",
 		"pressAnnotation": "Aキーを押して注釈を追加",
+		"pressAudio": "Mキーを押して音声を追加",
 		"pressSpeed": "Sキーを押して再生速度を追加",
 		"pressCameraFullscreen": "Cキーを押してフルスクリーンカメラのセグメントを追加"
 	},
diff --git a/src/i18n/locales/ko-KR/shortcuts.json b/src/i18n/locales/ko-KR/shortcuts.json
index 00e8f689d..82ec503ed 100644
--- a/src/i18n/locales/ko-KR/shortcuts.json
+++ b/src/i18n/locales/ko-KR/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "트림 추가",
 		"addSpeed": "속도 추가",
 		"addAnnotation": "주석 추가",
+		"addAudio": "오디오 추가",
 		"addKeyframe": "키프레임 추가",
 		"addCameraFullscreen": "전체 화면 카메라 추가",
 		"deleteSelected": "선택 항목 삭제",
diff --git a/src/i18n/locales/ko-KR/timeline.json b/src/i18n/locales/ko-KR/timeline.json
index 8a100ee6d..36daae802 100644
--- a/src/i18n/locales/ko-KR/timeline.json
+++ b/src/i18n/locales/ko-KR/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "Z를 눌러 줌 추가",
 		"pressTrim": "T를 눌러 트림 추가",
 		"pressAnnotation": "A를 눌러 주석 추가",
+		"pressAudio": "M을 눌러 오디오 추가",
 		"pressSpeed": "S를 눌러 속도 추가",
 		"pressCameraFullscreen": "C를 눌러 전체 화면 카메라 구간을 추가하세요"
 	},
diff --git a/src/i18n/locales/pt-BR/shortcuts.json b/src/i18n/locales/pt-BR/shortcuts.json
index a21fe7bed..ea7787c1d 100644
--- a/src/i18n/locales/pt-BR/shortcuts.json
+++ b/src/i18n/locales/pt-BR/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "Adicionar Recorte",
 		"addSpeed": "Adicionar Velocidade",
 		"addAnnotation": "Adicionar Anotação",
+		"addAudio": "Adicionar áudio",
 		"addKeyframe": "Adicionar Quadro-chave",
 		"addCameraFullscreen": "Adicionar Câmera em Tela Cheia",
 		"deleteSelected": "Excluir Selecionado",
diff --git a/src/i18n/locales/pt-BR/timeline.json b/src/i18n/locales/pt-BR/timeline.json
index 5359feba9..748ac7486 100644
--- a/src/i18n/locales/pt-BR/timeline.json
+++ b/src/i18n/locales/pt-BR/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "Pressione Z para adicionar zoom",
 		"pressTrim": "Pressione T para adicionar recorte",
 		"pressAnnotation": "Pressione A para adicionar anotação",
+		"pressAudio": "Pressione M para adicionar áudio",
 		"pressSpeed": "Pressione S para adicionar velocidade",
 		"pressCameraFullscreen": "Pressione C para adicionar um segmento de Câmera em Tela Cheia"
 	},
diff --git a/src/i18n/locales/ru/shortcuts.json b/src/i18n/locales/ru/shortcuts.json
index dabb06801..ce5747ea4 100644
--- a/src/i18n/locales/ru/shortcuts.json
+++ b/src/i18n/locales/ru/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "Добавить обрезку",
 		"addSpeed": "Изменить скорость",
 		"addAnnotation": "Добавить аннотацию",
+		"addAudio": "Добавить аудио",
 		"addKeyframe": "Добавить ключевой кадр",
 		"addCameraFullscreen": "Добавить камеру на весь экран",
 		"deleteSelected": "Удалить выбранное",
diff --git a/src/i18n/locales/ru/timeline.json b/src/i18n/locales/ru/timeline.json
index 387086953..8ee40a66c 100644
--- a/src/i18n/locales/ru/timeline.json
+++ b/src/i18n/locales/ru/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "Нажмите Z для добавления масштабирования",
 		"pressTrim": "Нажмите T для добавления обрезки",
 		"pressAnnotation": "Нажмите A для добавления аннотации",
+		"pressAudio": "Нажмите M, чтобы добавить аудио",
 		"pressSpeed": "Нажмите S для изменения скорости",
 		"pressCameraFullscreen": "Нажмите C, чтобы добавить сегмент камеры на весь экран"
 	},
diff --git a/src/i18n/locales/tr/shortcuts.json b/src/i18n/locales/tr/shortcuts.json
index 6b1db110d..b670fdbc4 100644
--- a/src/i18n/locales/tr/shortcuts.json
+++ b/src/i18n/locales/tr/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "Kırpma Ekle",
 		"addSpeed": "Hız Ekle",
 		"addAnnotation": "Açıklama Ekle",
+		"addAudio": "Ses ekle",
 		"addKeyframe": "Anahtar Kare Ekle",
 		"addCameraFullscreen": "Tam Ekran Kamera Ekle",
 		"deleteSelected": "Seçileni Sil",
diff --git a/src/i18n/locales/tr/timeline.json b/src/i18n/locales/tr/timeline.json
index d5a531f3e..2a6481612 100644
--- a/src/i18n/locales/tr/timeline.json
+++ b/src/i18n/locales/tr/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "Yakınlaştırma eklemek için Z tuşuna basın",
 		"pressTrim": "Kırpma eklemek için T tuşuna basın",
 		"pressAnnotation": "Açıklama eklemek için A tuşuna basın",
+		"pressAudio": "Ses eklemek için M'ye basın",
 		"pressSpeed": "Hız eklemek için S tuşuna basın",
 		"pressCameraFullscreen": "Tam Ekran Kamera bölümü eklemek için C tuşuna basın"
 	},
diff --git a/src/i18n/locales/vi/shortcuts.json b/src/i18n/locales/vi/shortcuts.json
index cf49f2526..6ffb15e98 100644
--- a/src/i18n/locales/vi/shortcuts.json
+++ b/src/i18n/locales/vi/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "Thêm Cắt",
 		"addSpeed": "Thêm Tốc độ",
 		"addAnnotation": "Thêm Chú thích",
+		"addAudio": "Thêm âm thanh",
 		"addKeyframe": "Thêm Khung hình chính",
 		"addCameraFullscreen": "Thêm Camera Toàn màn hình",
 		"deleteSelected": "Xóa mục đã chọn",
diff --git a/src/i18n/locales/vi/timeline.json b/src/i18n/locales/vi/timeline.json
index 1d963e585..25f55bd19 100644
--- a/src/i18n/locales/vi/timeline.json
+++ b/src/i18n/locales/vi/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "Nhấn Z để thêm thu phóng",
 		"pressTrim": "Nhấn T để thêm cắt",
 		"pressAnnotation": "Nhấn A để thêm chú thích",
+		"pressAudio": "Nhấn M để thêm âm thanh",
 		"pressSpeed": "Nhấn S để thêm tốc độ",
 		"pressCameraFullscreen": "Nhấn C để thêm một đoạn Camera Toàn màn hình"
 	},
diff --git a/src/i18n/locales/zh-CN/shortcuts.json b/src/i18n/locales/zh-CN/shortcuts.json
index 95ec1c07e..da2d95a5d 100644
--- a/src/i18n/locales/zh-CN/shortcuts.json
+++ b/src/i18n/locales/zh-CN/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "添加剪辑",
 		"addSpeed": "添加速度",
 		"addAnnotation": "添加标注",
+		"addAudio": "添加音频",
 		"addKeyframe": "添加关键帧",
 		"addCameraFullscreen": "添加全屏摄像头",
 		"deleteSelected": "删除所选",
diff --git a/src/i18n/locales/zh-CN/timeline.json b/src/i18n/locales/zh-CN/timeline.json
index 1451e6d31..9af9c1f96 100644
--- a/src/i18n/locales/zh-CN/timeline.json
+++ b/src/i18n/locales/zh-CN/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "按 Z 添加缩放",
 		"pressTrim": "按 T 添加剪辑",
 		"pressAnnotation": "按 A 添加标注",
+		"pressAudio": "按 M 添加音频",
 		"pressSpeed": "按 S 添加速度",
 		"pressCameraFullscreen": "按 C 添加一个全屏摄像头片段"
 	},
diff --git a/src/i18n/locales/zh-TW/shortcuts.json b/src/i18n/locales/zh-TW/shortcuts.json
index fd8c6434b..4819bee87 100644
--- a/src/i18n/locales/zh-TW/shortcuts.json
+++ b/src/i18n/locales/zh-TW/shortcuts.json
@@ -20,6 +20,7 @@
 		"addTrim": "新增剪輯",
 		"addSpeed": "新增速度",
 		"addAnnotation": "新增標註",
+		"addAudio": "新增音訊",
 		"addKeyframe": "新增關鍵影格",
 		"addCameraFullscreen": "新增全螢幕攝影機",
 		"deleteSelected": "刪除所選",
diff --git a/src/i18n/locales/zh-TW/timeline.json b/src/i18n/locales/zh-TW/timeline.json
index 7f4ba9874..7a632893e 100644
--- a/src/i18n/locales/zh-TW/timeline.json
+++ b/src/i18n/locales/zh-TW/timeline.json
@@ -15,6 +15,7 @@
 		"pressZoom": "按 Z 新增縮放",
 		"pressTrim": "按 T 新增剪輯",
 		"pressAnnotation": "按 A 新增標註",
+		"pressAudio": "按 M 新增音訊",
 		"pressSpeed": "按 S 新增速度",
 		"pressCameraFullscreen": "按 C 新增一個全螢幕攝影機片段"
 	},
diff --git a/src/lib/ai-edition/store/useTimeline.test.ts b/src/lib/ai-edition/store/useTimeline.test.ts
index 68bf29a97..0b0cb47cd 100644
--- a/src/lib/ai-edition/store/useTimeline.test.ts
+++ b/src/lib/ai-edition/store/useTimeline.test.ts
@@ -1407,6 +1407,34 @@ describe("useTimeline audio tracks", () => {
 		expect(useProjectStore.getState().document?.audioTracks).toEqual([]);
 	});
 
+	// #350: the toolbar button and the `M` shortcut both call `tl.addAudio`, which opens
+	// the OS file picker and hands the result to `importAudioAsset`. Spy on the store's
+	// import so these assert the wiring (picker → import), not the import itself.
+	it("addAudio imports the picked file, and is a no-op when the picker is cancelled", async () => {
+		const importSpy = vi.fn().mockResolvedValue(null);
+		useProjectStore.setState({ importAudioAsset: importSpy });
+		const pickerMock = vi.fn();
+		Object.defineProperty(window, "electronAPI", {
+			configurable: true,
+			value: { openAudioFilePicker: pickerMock },
+		});
+		const { result } = renderTimeline();
+
+		// Cancelled picker → nothing imported.
+		pickerMock.mockResolvedValueOnce({ success: false });
+		await act(async () => {
+			await result.current.addAudio();
+		});
+		expect(importSpy).not.toHaveBeenCalled();
+
+		// Picked a file → imported with its path and display name.
+		pickerMock.mockResolvedValueOnce({ success: true, path: "/tmp/bgm.mp3", name: "bgm.mp3" });
+		await act(async () => {
+			await result.current.addAudio();
+		});
+		expect(importSpy).toHaveBeenCalledWith("/tmp/bgm.mp3", "bgm.mp3");
+	});
+
 	// #350 regression: a failed import-time probe leaves durationSec at 0, which
 	// makes the playback window zero-length. The on-load backfill re-probes and
 	// stamps the real duration onto the asset AND the track, so it can play again.
diff --git a/src/lib/ai-edition/store/useTimeline.ts b/src/lib/ai-edition/store/useTimeline.ts
index df761bfed..e107f9b87 100644
--- a/src/lib/ai-edition/store/useTimeline.ts
+++ b/src/lib/ai-edition/store/useTimeline.ts
@@ -4,6 +4,7 @@
 // (a reasonable default for the user to then resize).
 
 import { useCallback, useEffect, useRef, useState } from "react";
+import { toast } from "sonner";
 import { toFileUrl } from "@/components/video-editor/projectPersistence";
 import type { AnnotationRegion, AnnotationType } from "@/components/video-editor/types";
 import { useScopedT } from "@/contexts/I18nContext";
@@ -118,6 +119,7 @@ export function useTimeline() {
 	const selectedAudioTrackId = useProjectStore((s) => s.selectedAudioTrackId);
 	const setSelectedAudioTrackId = useProjectStore((s) => s.setSelectedAudioTrackId);
 	const storeAddAudioTrack = useProjectStore((s) => s.addAudioTrack);
+	const importAudioAsset = useProjectStore((s) => s.importAudioAsset);
 	// Pre-drag snapshots for the two optimistic paths (zoom focus, annotations), so a
 	// failed commit can put the document back instead of leaving an edit on screen that
 	// was never written.
@@ -1276,6 +1278,23 @@ export function useTimeline() {
 		[storeAddAudioTrack],
 	);
 
+	// Import an audio file and drop it on the timeline (issue #350). Lives here — not in
+	// the timeline toolbar — so the toolbar button and the keyboard shortcut (both call
+	// through `tl`) share one path. Opens a file picker, so unlike the region adds it takes
+	// no playhead duration; `importAudioAsset` places the track at the current playhead.
+	const addAudio = useCallback(async () => {
+		const picker = await window.electronAPI?.openAudioFilePicker?.();
+		if (!picker?.success || !picker.path) return;
+		try {
+			const label = picker.name || picker.path.split(/[\\/]/).pop() || "Audio";
+			await importAudioAsset(picker.path, label);
+		} catch (err) {
+			toast.error(ts("audioTrack.importFailed"), {
+				description: err instanceof Error ? err.message : String(err),
+			});
+		}
+	}, [importAudioAsset, ts]);
+
 	const removeAudioTrack = useCallback(
 		async (trackId: string) => {
 			if (!document) return;
@@ -1335,6 +1354,7 @@ export function useTimeline() {
 		removeRegion,
 		removeRegions,
 		addAudioTrack,
+		addAudio,
 		removeAudioTrack,
 		placeAudioTrack,
 		setAudioTrackGain,
diff --git a/src/lib/shortcuts.ts b/src/lib/shortcuts.ts
index 0487b91c7..5617a1a3e 100644
--- a/src/lib/shortcuts.ts
+++ b/src/lib/shortcuts.ts
@@ -5,6 +5,7 @@ export const SHORTCUT_ACTIONS = [
 	"addSpeed",
 	"addCameraFullscreen",
 	"addAnnotation",
+	"addAudio",
 	"deleteSelected",
 	"playPause",
 	"copySelected",
@@ -113,6 +114,7 @@ export const DEFAULT_SHORTCUTS: ShortcutsConfig = {
 	addSpeed: { key: "s" },
 	addCameraFullscreen: { key: "c" },
 	addAnnotation: { key: "a" },
+	addAudio: { key: "m" },
 	deleteSelected: { key: "d", ctrl: true },
 	playPause: { key: " " },
 	copySelected: { key: "c", ctrl: true },
@@ -126,6 +128,7 @@ export const SHORTCUT_LABELS: Record<ShortcutAction, string> = {
 	addSpeed: "Add Speed",
 	addCameraFullscreen: "Add Full Camera",
 	addAnnotation: "Add Annotation",
+	addAudio: "Add Audio",
 	deleteSelected: "Delete Selected",
 	playPause: "Play / Pause",
 	copySelected: "Copy Selected",

From ee6818657baf2d1a3dae51be3161490275b8e0d7 Mon Sep 17 00:00:00 2001
From: Benjamin Freeman <bfreeman@operametrix.fr>
Date: Tue, 25 Aug 2026 21:53:46 +0200
Subject: [PATCH 20/20] fix(editor): sync imported audio tracks to trims in the
 export (issue #350)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

An imported audio track stores its head in RAW timeline seconds (seeded from
the playhead), but the exporter mixes it onto the trim-COMPRESSED programme.
The scene builder passed the raw head straight through as the output offset,
so every cut ahead of a track delayed it in the render by exactly the removed
duration — the reported "the following audio track was delayed by the trim
duration once rendered". The preview never showed this because its playhead
jumps across a trim, landing the track on time.

Project the raw head onto the programme before handing it to the compositor:
output(T) = T − (trimmed span before T), a new pure
`projectRawTimelineSecToPlayback` that walks clips+trims with the same
source-time model as `resolvePlaybackSegments`. Exact for trims; speed
regions remain the pre-existing approximation. Regions with no trim — a
project with no clips included — pass through unchanged.

Corrects the two stale comments that claimed the raw positions "agree" with
the export (they only did without trims). Adds unit coverage for the
projector (before/after/inside a cut, multi-clip) and an end-to-end scene
test pinning a track's head onto the compressed programme.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 src/components/ai-edition/VirtualPreview.tsx |  5 +-
 src/lib/ai-edition/document/timeline.test.ts | 55 ++++++++++++++++++++
 src/lib/ai-edition/document/timeline.ts      | 46 ++++++++++++++++
 src/native/sceneDescription.test.ts          | 28 ++++++++++
 src/native/sceneDescription.ts               | 23 +++++---
 5 files changed, 150 insertions(+), 7 deletions(-)

diff --git a/src/components/ai-edition/VirtualPreview.tsx b/src/components/ai-edition/VirtualPreview.tsx
index 44bb0fd69..a064821eb 100644
--- a/src/components/ai-edition/VirtualPreview.tsx
+++ b/src/components/ai-edition/VirtualPreview.tsx
@@ -83,7 +83,10 @@ export function resolveAudioTrackPlayback(
  * This is the RAW/document timeline the ruler, playhead and lane all use — NOT
  * the trim-compressed output timeline — because that is where the track was
  * placed (`useTimeline.addAudioTrack` seeds `timelineStartSec` from the playhead).
- * The export mixes on the same RAW positions (see audio.rs), so the two agree.
+ * The preview's playhead JUMPS across a trim, so a track at a raw head past a cut
+ * still fires at the right wall-clock moment here. The export mixes onto the
+ * compressed programme, so it projects the raw head through the trims first
+ * (`projectRawTimelineSecToPlayback` in sceneDescription) to land at the same place.
  */
 export function resolveTimelineAudioPlayback(virtualTimeSec: number, track: AxcutAudioTrack) {
 	const trimStart = Math.max(0, track.trimStartSec);
diff --git a/src/lib/ai-edition/document/timeline.test.ts b/src/lib/ai-edition/document/timeline.test.ts
index bb5172178..7a6704fd8 100644
--- a/src/lib/ai-edition/document/timeline.test.ts
+++ b/src/lib/ai-edition/document/timeline.test.ts
@@ -13,6 +13,7 @@ import {
 	normalizeIntervals,
 	planTimelineReplacement,
 	primaryAssetDuration,
+	projectRawTimelineSecToPlayback,
 	rederiveRegionMs,
 	removeClip,
 	removeRegion,
@@ -841,6 +842,60 @@ describe("resolvePlaybackSegments", () => {
 	});
 });
 
+describe("projectRawTimelineSecToPlayback (issue #350 audio-track/trim sync)", () => {
+	// One 10s clip, an interior trim removing raw 2..4 (2s). Output programme is 8s long.
+	const clip = makeClip({
+		sourceStartSec: 0,
+		sourceEndSec: 10,
+		timelineStartSec: 0,
+		timelineEndSec: 10,
+	});
+	const trim = makeTrim({ startSec: 2, endSec: 4 });
+
+	it("is the identity when there are no trims", () => {
+		expect(projectRawTimelineSecToPlayback([clip], [], 6)).toBeCloseTo(6, 6);
+	});
+
+	it("pulls a raw position after a cut earlier by the removed duration", () => {
+		// Raw 6 sits 2s past the 2s cut → output 4. This is the exact bug: the track was
+		// landing at 6 (delayed by the trim) instead of 4.
+		expect(projectRawTimelineSecToPlayback([clip], [trim], 6)).toBeCloseTo(4, 6);
+	});
+
+	it("is unaffected for a position before the cut", () => {
+		expect(projectRawTimelineSecToPlayback([clip], [trim], 1)).toBeCloseTo(1, 6);
+	});
+
+	it("collapses a position inside the trimmed gap to the end of the kept content before it", () => {
+		// Raw 3 is inside the removed 2..4 span → the next audible sample is at output 2.
+		expect(projectRawTimelineSecToPlayback([clip], [trim], 3)).toBeCloseTo(2, 6);
+	});
+
+	it("sums cuts across multiple clips", () => {
+		const clipA = makeClip({
+			id: "clip_a",
+			sourceStartSec: 0,
+			sourceEndSec: 10,
+			timelineStartSec: 0,
+			timelineEndSec: 10,
+		});
+		const clipB = makeClip({
+			id: "clip_b",
+			sourceStartSec: 10,
+			sourceEndSec: 20,
+			timelineStartSec: 10,
+			timelineEndSec: 20,
+		});
+		// Remove 1s from clip A (raw 5..6) and 2s from clip B (raw 12..14) → 3s total.
+		const trims = [
+			makeTrim({ id: "t1", startSec: 5, endSec: 6 }),
+			makeTrim({ id: "t2", startSec: 12, endSec: 14 }),
+		];
+		// Raw 18 is past both cuts (3s removed) → output 15.
+		expect(projectRawTimelineSecToPlayback([clipA, clipB], trims, 18)).toBeCloseTo(15, 6);
+	});
+});
+
 describe("duplicateClip / moveClip", () => {
 	it("duplicateClip gives the copy a fresh, collision-free id even when called repeatedly", () => {
 		// Regression test: this used to id the copy as `clip_${clips.length + 1}_copy`,
diff --git a/src/lib/ai-edition/document/timeline.ts b/src/lib/ai-edition/document/timeline.ts
index 232bcb6ee..0cbbeabd4 100644
--- a/src/lib/ai-edition/document/timeline.ts
+++ b/src/lib/ai-edition/document/timeline.ts
@@ -202,6 +202,52 @@ export function resolvePlaybackSegments(
 	return result;
 }
 
+/**
+ * Project a RAW/document-timeline second (the ruler where trims still occupy their space)
+ * onto the trim-COMPRESSED output programme — the concatenation of the kept segments that
+ * {@link resolvePlaybackSegments} produces and that `audio::mix_external_tracks` overlays on.
+ *
+ * The only thing the programme removes is trimmed content, so the output position of a raw
+ * time `T` is `T` minus however much trimmed span sits before it:
+ *   `output(T) = T − Σ overlap(each trim's raw extent, [0, T])`.
+ * A `T` past a cut lands earlier by exactly the removed duration (the whole point); a `T`
+ * INSIDE a trimmed span collapses to the output edge just before it; and a `T` in a region
+ * with no trim — including a project with no clips at all — passes straight through.
+ *
+ * A trim is stored in SOURCE seconds anchored to a clip (`trimAppliesToClip`, same match as
+ * `resolvePlaybackSegments`), so its raw extent is the clip's `timelineStartSec` plus the
+ * offset of the trimmed sub-range into the clip's own source window. EXACT for trims; like the
+ * rest of the audio-track export path it does not model speed regions, which stay an approximation.
+ *
+ * Issue #350: imported audio tracks store their head in RAW seconds (seeded from the playhead),
+ * but the export mixes onto the compressed programme — passing the raw head through verbatim
+ * delayed every track by the total trim duration ahead of it. The preview already lands them
+ * correctly because its playhead jumps across trims; this makes the render agree.
+ */
+export function projectRawTimelineSecToPlayback(
+	clips: AxcutClip[],
+	trimRanges: AxcutTrimRange[],
+	rawSec: number,
+): number {
+	let removed = 0;
+	for (const clip of clips) {
+		const sourceEnd = clip.sourceEndSec ?? clip.sourceStartSec;
+		if (sourceEnd <= clip.sourceStartSec) continue; // unprobed: no trims resolved against it
+		for (const trim of trimRanges) {
+			if (!trimAppliesToClip(trim, clip)) continue;
+			// The trimmed sub-range clamped to THIS clip's source window, then placed on the raw
+			// ruler where source `s` sits at `timelineStartSec + (s − sourceStartSec)`.
+			const s0 = Math.max(trim.startSec, clip.sourceStartSec);
+			const s1 = Math.min(trim.endSec, sourceEnd);
+			if (s1 <= s0) continue;
+			const rawStart = clip.timelineStartSec + (s0 - clip.sourceStartSec);
+			const rawLen = s1 - s0;
+			removed += Math.min(Math.max(rawSec - rawStart, 0), rawLen);
+		}
+	}
+	return rawSec - removed;
+}
+
 export function invertIntervals(intervals: Interval[], durationSec: number): Interval[] {
 	const cuts: Interval[] = [];
 	let cursor = 0;
diff --git a/src/native/sceneDescription.test.ts b/src/native/sceneDescription.test.ts
index 5d666c87c..0140fb476 100644
--- a/src/native/sceneDescription.test.ts
+++ b/src/native/sceneDescription.test.ts
@@ -1831,6 +1831,34 @@ describe("buildSceneDescription.audioTracks", () => {
 		expect(buildSceneDescription(doc).audioTracks[0]?.trimEndSec).toBe(30);
 	});
 
+	it("projects the head onto the trim-compressed programme (issue #350)", () => {
+		// A 10s screen clip with an interior cut removing raw [2,4] (2s). The audio track's
+		// raw head is 5; on the compressed programme that is 3. Passing 5 through verbatim was
+		// the bug — the track played 2s (the trim) late in the render while the preview, whose
+		// playhead jumps the cut, had it on time.
+		const screen = makeAsset({ id: "scr", originalPath: "/screen.mp4", durationSec: 10 });
+		const doc = makeDoc({
+			assets: [screen, audioAsset],
+			clips: [
+				makeClip({
+					id: "c1",
+					assetId: "scr",
+					sourceStartSec: 0,
+					sourceEndSec: 10,
+					timelineStartSec: 0,
+					timelineEndSec: 10,
+				}),
+			],
+			timeline: {
+				trimRanges: [
+					{ id: "t1", assetId: "scr", startSec: 2, endSec: 4, reason: "", origin: "user" },
+				],
+			},
+			audioTracks: [track],
+		});
+		expect(buildSceneDescription(doc).audioTracks[0]?.startSec).toBeCloseTo(3, 6);
+	});
+
 	it("drops a track whose asset has no resolvable path", () => {
 		const doc = makeDoc({ assets: [], audioTracks: [track] });
 		expect(buildSceneDescription(doc).audioTracks).toEqual([]);
diff --git a/src/native/sceneDescription.ts b/src/native/sceneDescription.ts
index 8ee9e3e07..d190fda5e 100644
--- a/src/native/sceneDescription.ts
+++ b/src/native/sceneDescription.ts
@@ -26,7 +26,10 @@ import {
 } from "@/lib/ai-edition/captions";
 import { createId } from "@/lib/ai-edition/document/ids";
 import { pickOutputDims } from "@/lib/ai-edition/document/outputFormat";
-import { resolvePlaybackSegments } from "@/lib/ai-edition/document/timeline";
+import {
+	projectRawTimelineSecToPlayback,
+	resolvePlaybackSegments,
+} from "@/lib/ai-edition/document/timeline";
 import type { AxcutClip, AxcutDocument } from "@/lib/ai-edition/schema";
 import { getEditorSettings } from "@/lib/ai-edition/store/editorSettings";
 import { assetCameraSource } from "@/lib/ai-edition/timeline/camera";
@@ -393,10 +396,11 @@ export interface SceneDescription {
 	};
 	/**
 	 * Imported audio tracks (issue #350), mixed over the assembled programme by
-	 * `audio::mix_external_tracks`. `startSec` is the head on the OUTPUT programme;
-	 * it equals the track's raw timeline position, which is exact when the project
-	 * has no trims/speed and an accepted approximation otherwise (the preview
-	 * approximates the same way). `trimEndSec` is always concrete — the compositor
+	 * `audio::mix_external_tracks`. `startSec` is the head on the trim-COMPRESSED output
+	 * programme: the track's raw timeline head projected through the trims via
+	 * `projectRawTimelineSecToPlayback`, so a cut ahead of the track pulls it earlier by the
+	 * removed duration (exactly as the preview already plays it). Exact for trims; speed
+	 * regions stay an approximation. `trimEndSec` is always concrete — the compositor
 	 * preallocates the decode window from it — so it is resolved to the source
 	 * duration when the track's tail isn't trimmed.
 	 */
@@ -476,7 +480,14 @@ export function buildSceneDescription(
 		return [
 			{
 				path: asset.originalPath,
-				startSec: track.timelineStartSec,
+				// The track's head is stored in RAW timeline seconds, but the programme this
+				// mixes onto is trim-compressed — so project raw→output. Passing the raw head
+				// verbatim delayed the track by the total trim duration ahead of it (issue #350).
+				startSec: projectRawTimelineSecToPlayback(
+					document.timeline.clips,
+					document.timeline.trimRanges,
+					track.timelineStartSec,
+				),
 				gainDb: track.gainDb,
 				trimStartSec: track.trimStartSec,
 				trimEndSec,