fix(workflows): multi-input nodes drop their audio slot

src/areas/workflows/slotInputs.test.mjs

@@ -0,0 +1,54 @@
+import test from 'node:test'
+import assert from 'node:assert/strict'
+import { buildSync } from 'esbuild'
+import { createRequire } from 'node:module'
+import { mkdtempSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join, resolve } from 'node:path'
+
+// slotInputs.ts has no runtime imports, so esbuild bundles it standalone.
+function loadModule() {
+  const outfile = join(mkdtempSync(join(tmpdir(), 'modly-slotinputs-test-')), 'slotInputs.cjs')
+  const require = createRequire(import.meta.url)
+  const result = buildSync({
+    entryPoints: [resolve('src/areas/workflows/slotInputs.ts')],
+    bundle: true,
+    platform: 'node',
+    format: 'cjs',
+    write: false,
+  })
+  writeFileSync(outfile, result.outputFiles[0].text, 'utf8')
+  return require(outfile)
+}
+
+const { assignSlotFilePaths } = loadModule()
+
+test('a mesh slot becomes the mesh path', () => {
+  const r = assignSlotFilePaths(['mesh', 'image'], ['a.glb', 'b.png'])
+  assert.equal(r.nodeInputMeshPath, 'a.glb')
+  assert.equal(r.nodeInputPath, 'b.png')
+  assert.deepEqual(r.extraImagePaths, [])
+})
+
+test('the first image slot is the primary path and later images are extras', () => {
+  const r = assignSlotFilePaths(['image', 'image', 'image'], ['1.png', '2.png', '3.png'])
+  assert.equal(r.nodeInputPath, '1.png')
+  assert.deepEqual(r.extraImagePaths, ['2.png', '3.png'])
+  assert.equal(r.nodeInputMeshPath, undefined)
+})
+
+test('an audio slot becomes the primary path', () => {
+  // Regression: audio slots were resolved and then dropped, so a multi-input
+  // node such as [audio, text] failed with "needs an incoming audio connection".
+  const r = assignSlotFilePaths(['audio', 'text'], ['song.wav', undefined])
+  assert.equal(r.nodeInputPath, 'song.wav')
+  assert.equal(r.nodeInputMeshPath, undefined)
+  assert.deepEqual(r.extraImagePaths, [])
+})
+
+test('text slots never claim a file path, and empty slots are skipped', () => {
+  const r = assignSlotFilePaths(['text', 'image'], ['leaked.png', undefined])
+  assert.equal(r.nodeInputPath, undefined)
+  assert.equal(r.nodeInputMeshPath, undefined)
+  assert.deepEqual(r.extraImagePaths, [])
+})

src/areas/workflows/slotInputs.ts

@@ -0,0 +1,36 @@
+// Multi-input slot → file-path assignment for extension nodes.
+//
+// `inputTypes` is the node's declared `inputs` (one per handle); `inputPaths` is
+// the file path resolved for each slot, indexed the same way (undefined where the
+// slot carries text or nothing). Pure so it can be tested without the store.
+
+export type SlotInputType = 'image' | 'text' | 'mesh' | 'audio'
+
+export interface SlotFilePaths {
+  /** Primary file: what the extension receives as `filePath` when no mesh is present. */
+  nodeInputPath?:     string
+  /** Mesh slot, if any. Takes precedence as `filePath`; the primary file then rides in params. */
+  nodeInputMeshPath?: string
+  /** Every image beyond the first resolved image slot. */
+  extraImagePaths:    string[]
+}
+
+export function assignSlotFilePaths(
+  inputTypes: readonly SlotInputType[],
+  inputPaths: readonly (string | undefined)[],
+): SlotFilePaths {
+  const out: SlotFilePaths = { extraImagePaths: [] }
+  for (let i = 0; i < inputTypes.length; i++) {
+    const fp = inputPaths[i]
+    if (!fp) continue
+    if (inputTypes[i] === 'mesh') {
+      out.nodeInputMeshPath = fp
+    } else if (inputTypes[i] === 'image') {
+      if (!out.nodeInputPath) out.nodeInputPath = fp
+      else out.extraImagePaths.push(fp)
+    } else if (inputTypes[i] === 'audio') {
+      if (!out.nodeInputPath) out.nodeInputPath = fp
+    }
+  }
+  return out
+}

src/areas/workflows/workflowRunStore.ts

@@ -6,6 +6,7 @@ import { showCompletionNotification } from '@shared/utils/notification'
 import type { WorkflowExtension } from './mockExtensions'
 import type { Workflow, WFNode, WFEdge } from '@shared/types/electron.d'
 import { isBranchStarter, isSceneOutput, resolveDataSource, reachesSceneOutput, nearestUpstreamWaits } from './nodeBehaviors'
+import { assignSlotFilePaths } from './slotInputs'
 
 // ─── Types ────────────────────────────────────────────────────────────────────
 
@@ -344,16 +345,10 @@ async function executeExtensionNode(
       }
     }
 
-    for (let i = 0; i < inputTypes.length; i++) {
-      const fp = inputPaths[i]
-      if (!fp) continue
-      if (inputTypes[i] === 'mesh') {
-        nodeInputMeshPath = fp
-      } else if (inputTypes[i] === 'image') {
-        if (!nodeInputPath) nodeInputPath = fp
-        else extraImagePaths.push(fp)
-      }
-    }
+    const slots = assignSlotFilePaths(inputTypes, inputPaths)
+    nodeInputPath     = slots.nodeInputPath
+    nodeInputMeshPath = slots.nodeInputMeshPath
+    extraImagePaths.push(...slots.extraImagePaths)
   } else {
     for (const edge of incomingEdges) {
       const src = resolveSource(edge.source)