diff --git a/packages/metadata/package.json b/packages/metadata/package.json
index 4ac2213264..5b591ba4ab 100644
--- a/packages/metadata/package.json
+++ b/packages/metadata/package.json
@@ -57,6 +57,7 @@
     "build": "tsup && node ../../scripts/check-dts-emitted.mjs",
     "dev": "tsc --watch",
     "clean": "rm -rf dist",
+    "typecheck": "tsc --noEmit",
     "test": "vitest run",
     "test:watch": "vitest",
     "test:coverage": "vitest run --coverage"
diff --git a/packages/metadata/src/loaders/database-loader.test.ts b/packages/metadata/src/loaders/database-loader.test.ts
index 832042b655..e6263ea0eb 100644
--- a/packages/metadata/src/loaders/database-loader.test.ts
+++ b/packages/metadata/src/loaders/database-loader.test.ts
@@ -1,10 +1,10 @@
 // Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
 
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
-import { DatabaseLoader, type DatabaseLoaderOptions } from './database-loader';
+import { DatabaseLoader } from './database-loader.js';
 import type { IDataDriver } from '@objectstack/spec/contracts';
-import { MetadataManager } from '../metadata-manager';
-import { MemoryLoader } from './memory-loader';
+import { MetadataManager } from '../metadata-manager.js';
+import { MemoryLoader } from './memory-loader.js';
 
 // Suppress logger output during tests. Stable object (not a fresh one per
 // `createLogger()` call) so the #5108 block can assert on what `list()` says
diff --git a/packages/metadata/src/loaders/overlay-index-single-producer.test.ts b/packages/metadata/src/loaders/overlay-index-single-producer.test.ts
index 8f6f2597cc..0efa059293 100644
--- a/packages/metadata/src/loaders/overlay-index-single-producer.test.ts
+++ b/packages/metadata/src/loaders/overlay-index-single-producer.test.ts
@@ -43,7 +43,7 @@
  */
 
 import { describe, it, expect } from 'vitest';
-import { DatabaseLoader } from './database-loader';
+import { DatabaseLoader } from './database-loader.js';
 import { SqliteWasmDriver } from '@objectstack/driver-sqlite-wasm';
 
 const INDEX = 'idx_sys_metadata_overlay_active';
diff --git a/packages/metadata/src/metadata-history.test.ts b/packages/metadata/src/metadata-history.test.ts
index 193ef648d8..404a3a499a 100644
--- a/packages/metadata/src/metadata-history.test.ts
+++ b/packages/metadata/src/metadata-history.test.ts
@@ -1,8 +1,8 @@
 // Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
 
 import { describe, it, expect, beforeEach } from 'vitest';
-import { MetadataManager } from './metadata-manager';
-import { DatabaseLoader } from './loaders/database-loader';
+import { MetadataManager } from './metadata-manager.js';
+import { DatabaseLoader } from './loaders/database-loader.js';
 import { SqliteWasmDriver } from '@objectstack/driver-sqlite-wasm';
 
 describe('Metadata History', () => {
@@ -147,7 +147,7 @@ describe('Metadata History', () => {
       const diffResult = await manager.diff('object', 'test_object', 1, 2);
 
       expect(diffResult.identical).toBe(false);
-      expect(diffResult.patch.length).toBeGreaterThan(0);
+      expect(diffResult.patch!.length).toBeGreaterThan(0);
       expect(diffResult.summary).toContain('modified');
     }
   });
diff --git a/packages/metadata/src/metadata-manager-cluster.test.ts b/packages/metadata/src/metadata-manager-cluster.test.ts
index d4812e5f55..1b702e6c0c 100644
--- a/packages/metadata/src/metadata-manager-cluster.test.ts
+++ b/packages/metadata/src/metadata-manager-cluster.test.ts
@@ -1,8 +1,8 @@
 // Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
 
 import { describe, it, expect, vi } from 'vitest';
-import { MetadataManager } from './metadata-manager';
-import { MemoryLoader } from './loaders/memory-loader';
+import { MetadataManager } from './metadata-manager.js';
+import { MemoryLoader } from './loaders/memory-loader.js';
 import type { MetadataLoader } from './loaders/loader-interface.js';
 import type { MetadataLoaderContract, MetadataLoadResult, MetadataSaveResult, MetadataStats } from '@objectstack/spec/system';
 import type { IPubSub, PubSubMessage } from '@objectstack/spec/contracts';
@@ -172,8 +172,8 @@ describe('MetadataManager — cluster pub/sub bridge', () => {
 
         const a: unknown[] = [];
         const b: unknown[] = [];
-        mgrA.subscribe('object', (e) => a.push(e));
-        mgrB.subscribe('object', (e) => b.push(e));
+        mgrA.subscribe('object', (e) => { a.push(e); });
+        mgrB.subscribe('object', (e) => { b.push(e); });
 
         // Simulate manager A emitting a watch event by going through the
         // public publish surface directly (we don't have a repository
@@ -197,7 +197,7 @@ describe('MetadataManager — cluster pub/sub bridge', () => {
         mgr.attachClusterPubSub(bus, 'node-B');
 
         const received: unknown[] = [];
-        mgr.subscribe('object', (e) => received.push(e));
+        mgr.subscribe('object', (e) => { received.push(e); });
 
         mgr.detachClusterPubSub();
         mgr.detachClusterPubSub(); // idempotent
@@ -220,7 +220,7 @@ describe('MetadataManager — cluster pub/sub bridge', () => {
         const off2 = mgr.attachClusterPubSub(bus, 'node-B'); // should not double-subscribe
 
         const received: unknown[] = [];
-        mgr.subscribe('object', (e) => received.push(e));
+        mgr.subscribe('object', (e) => { received.push(e); });
 
         await bus.publish('metadata.changed', {
             originNode: 'node-A',
@@ -239,7 +239,7 @@ describe('MetadataManager — cluster pub/sub bridge', () => {
         mgr.attachClusterPubSub(bus, 'node-B');
 
         const received: unknown[] = [];
-        mgr.subscribe('object', (e) => received.push(e));
+        mgr.subscribe('object', (e) => { received.push(e); });
 
         await bus.publish('metadata.changed', { originNode: 'node-A' }); // missing type/event
         await bus.publish('metadata.changed', null);
diff --git a/packages/metadata/src/metadata-realtime-events.test.ts b/packages/metadata/src/metadata-realtime-events.test.ts
index c61e4cc9ca..17380e100e 100644
--- a/packages/metadata/src/metadata-realtime-events.test.ts
+++ b/packages/metadata/src/metadata-realtime-events.test.ts
@@ -24,8 +24,8 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { MetadataEventSchema } from '@objectstack/spec/api';
 import type { IRealtimeService, RealtimeEventPayload } from '@objectstack/spec/contracts';
-import { MetadataManager } from './metadata-manager';
-import { MemoryLoader } from './loaders/memory-loader';
+import { MetadataManager } from './metadata-manager.js';
+import { MemoryLoader } from './loaders/memory-loader.js';
 import { DEFAULT_METADATA_TYPE_REGISTRY } from '@objectstack/spec/kernel';
 
 vi.mock('@objectstack/core', async (orig) => ({
diff --git a/packages/metadata/src/metadata-service.test.ts b/packages/metadata/src/metadata-service.test.ts
index d0f441cf56..e1116c6ac4 100644
--- a/packages/metadata/src/metadata-service.test.ts
+++ b/packages/metadata/src/metadata-service.test.ts
@@ -1,8 +1,8 @@
 // Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
 
 import { describe, it, expect, vi, beforeEach } from 'vitest';
-import { MetadataManager } from './metadata-manager';
-import { MemoryLoader } from './loaders/memory-loader';
+import { MetadataManager } from './metadata-manager.js';
+import { MemoryLoader } from './loaders/memory-loader.js';
 import { DEFAULT_METADATA_TYPE_REGISTRY } from '@objectstack/spec/kernel';
 
 // Suppress logger output during tests
diff --git a/packages/metadata/src/metadata.test.ts b/packages/metadata/src/metadata.test.ts
index 30cc3e85ed..14d48f664a 100644
--- a/packages/metadata/src/metadata.test.ts
+++ b/packages/metadata/src/metadata.test.ts
@@ -4,9 +4,9 @@ import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { mkdtempSync, rmSync, writeFileSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
-import { MetadataManager } from './metadata-manager';
-import { MemoryLoader } from './loaders/memory-loader';
-import type { MetadataLoader } from './loaders/loader-interface';
+import { MetadataManager } from './metadata-manager.js';
+import { MemoryLoader } from './loaders/memory-loader.js';
+import type { MetadataLoader } from './loaders/loader-interface.js';
 
 // Suppress logger output during tests
 vi.mock('@objectstack/core', async (orig) => ({
@@ -953,6 +953,11 @@ function createMockLoaderMany(name: string, items: any[], shouldFail = false): M
 function createMockPluginContext() {
   return {
     registerService: vi.fn(),
+    // Required members of `PluginContext` (@objectstack/core) that this suite
+    // never drives — inert stubs so the literal satisfies the parameter type
+    // rather than 30 call sites each asserting past it.
+    registerServiceFactory: vi.fn(),
+    getServiceScoped: vi.fn(),
     replaceService: vi.fn(),
     getService: vi.fn().mockReturnValue(null),
     getServices: vi.fn().mockReturnValue(new Map()),
diff --git a/packages/metadata/src/plugin-hmr-reload.test.ts b/packages/metadata/src/plugin-hmr-reload.test.ts
index 0927d96916..be07f88bec 100644
--- a/packages/metadata/src/plugin-hmr-reload.test.ts
+++ b/packages/metadata/src/plugin-hmr-reload.test.ts
@@ -12,8 +12,8 @@ import { describe, it, expect, vi } from 'vitest';
 import { mkdtempSync, writeFileSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
-import { MetadataPlugin } from './plugin';
-import type { NodeMetadataManager } from './node-metadata-manager';
+import { MetadataPlugin } from './plugin.js';
+import type { NodeMetadataManager } from './node-metadata-manager.js';
 
 function fakeCtx() {
     return {
@@ -111,7 +111,7 @@ describe('MetadataPlugin._reloadAndAnnounce — fires metadata:reloaded after re
         const file = writeArtifact('sweep3');
 
         const perItemEvents: unknown[] = [];
-        mgr.subscribe('flow', (evt) => perItemEvents.push(evt));
+        mgr.subscribe('flow', (evt) => { perItemEvents.push(evt); });
 
         await (plugin as any)._reloadAndAnnounce(ctx, { path: file, fetchTimeoutMs: undefined }, [file]);
 
diff --git a/packages/metadata/src/plugin.test.ts b/packages/metadata/src/plugin.test.ts
index c0268b8a6d..8b795b4f83 100644
--- a/packages/metadata/src/plugin.test.ts
+++ b/packages/metadata/src/plugin.test.ts
@@ -1,8 +1,8 @@
 // Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
 
 import { describe, it, expect, vi } from 'vitest';
-import { MetadataPlugin } from './plugin';
-import { NodeMetadataManager } from './node-metadata-manager';
+import { MetadataPlugin } from './plugin.js';
+import { NodeMetadataManager } from './node-metadata-manager.js';
 
 vi.mock('@objectstack/core', async (orig) => {
     const real = (await orig()) as any;
diff --git a/packages/metadata/src/register-notifies-watchers.test.ts b/packages/metadata/src/register-notifies-watchers.test.ts
index b549b979a9..1a07faff82 100644
--- a/packages/metadata/src/register-notifies-watchers.test.ts
+++ b/packages/metadata/src/register-notifies-watchers.test.ts
@@ -50,15 +50,16 @@ import type {
   MetadataStats,
   MetadataWatchEvent,
 } from '@objectstack/spec/system';
-import { MetadataManager } from './metadata-manager';
-import { MemoryLoader } from './loaders/memory-loader';
-// `.js` deliberately, unlike the three extensionless imports above it: under
-// `moduleResolution: nodenext` an extensionless relative import does not
+import { MetadataManager } from './metadata-manager.js';
+import { MemoryLoader } from './loaders/memory-loader.js';
+// `.js` on this relative import, as on every relative import in this file:
+// under `moduleResolution: nodenext` an extensionless relative import does not
 // resolve, and every symbol it names silently becomes `any` (AGENTS.md, the
-// TS7006 cascade). Spelling this one correctly is what makes `implements
+// TS7006 cascade). Spelling it correctly is what makes `implements
 // MetadataLoader` on the fixture below an actual check rather than decoration.
-// The three above are this package's pre-existing type-check debt (#4311) and
-// are left for whoever pays that ledger down.
+// That is no longer a convention this file keeps on its own: the package
+// declares a `typecheck` script, so `turbo run typecheck` compiles this file
+// and an extensionless relative import here is a red gate, not a silent `any`.
 import type { MetadataLoader } from './loaders/loader-interface.js';
 import { DEFAULT_METADATA_TYPE_REGISTRY } from '@objectstack/spec/kernel';
 
@@ -205,7 +206,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
   describe('register()', () => {
     it('announces a first registration as "added"', async () => {
       const seen: any[] = [];
-      manager.subscribe('object', (evt) => seen.push(evt));
+      manager.subscribe('object', (evt) => { seen.push(evt); });
 
       await manager.register('object', 'account', { name: 'account', label: 'Account' });
 
@@ -222,7 +223,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
       await manager.register('object', 'account', { name: 'account', label: 'V1' });
 
       const seen: any[] = [];
-      manager.subscribe('object', (evt) => seen.push(evt));
+      manager.subscribe('object', (evt) => { seen.push(evt); });
 
       await manager.register('object', 'account', { name: 'account', label: 'V2' });
 
@@ -290,7 +291,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
 
     it('is silent when the caller opts out with { notify: false }', async () => {
       const seen: any[] = [];
-      manager.subscribe('object', (evt) => seen.push(evt));
+      manager.subscribe('object', (evt) => { seen.push(evt); });
 
       await manager.register('object', 'account', { name: 'account' }, { notify: false });
 
@@ -302,8 +303,8 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
     it('only notifies watchers of the written type', async () => {
       const objects: any[] = [];
       const views: any[] = [];
-      manager.subscribe('object', (evt) => objects.push(evt));
-      manager.subscribe('view', (evt) => views.push(evt));
+      manager.subscribe('object', (evt) => { objects.push(evt); });
+      manager.subscribe('view', (evt) => { views.push(evt); });
 
       await manager.register('object', 'account', { name: 'account' });
 
@@ -320,7 +321,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
       readOnly.setTypeRegistry(DEFAULT_METADATA_TYPE_REGISTRY);
 
       const seen: any[] = [];
-      readOnly.subscribe('object', (evt) => seen.push(evt));
+      readOnly.subscribe('object', (evt) => { seen.push(evt); });
 
       await readOnly.register('object', 'account', { name: 'account' });
 
@@ -340,7 +341,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
 
     it('stops notifying after unsubscribe', async () => {
       const seen: any[] = [];
-      const off = manager.subscribe('object', (evt) => seen.push(evt));
+      const off = manager.subscribe('object', (evt) => { seen.push(evt); });
 
       await manager.register('object', 'a', { name: 'a' });
       off();
@@ -356,7 +357,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
       await manager.register('object', 'account', { name: 'account' });
 
       const seen: any[] = [];
-      manager.subscribe('object', (evt) => seen.push(evt));
+      manager.subscribe('object', (evt) => { seen.push(evt); });
 
       await manager.unregister('object', 'account');
 
@@ -372,7 +373,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
       await manager.register('object', 'account', { name: 'account' }, { notify: false });
 
       const seen: any[] = [];
-      manager.subscribe('object', (evt) => seen.push(evt));
+      manager.subscribe('object', (evt) => { seen.push(evt); });
 
       await manager.unregister('object', 'account', { notify: false });
 
@@ -384,7 +385,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
   describe('bulk forms', () => {
     it('bulkRegister announces one event per item by default', async () => {
       const seen: any[] = [];
-      manager.subscribe('object', (evt) => seen.push(evt));
+      manager.subscribe('object', (evt) => { seen.push(evt); });
 
       await manager.bulkRegister([
         { type: 'object', name: 'a', data: { name: 'a' } },
@@ -396,7 +397,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
 
     it('bulkRegister forwards { notify: false } to every item', async () => {
       const seen: any[] = [];
-      manager.subscribe('object', (evt) => seen.push(evt));
+      manager.subscribe('object', (evt) => { seen.push(evt); });
 
       await manager.bulkRegister(
         [
@@ -420,7 +421,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
       );
 
       const seen: any[] = [];
-      manager.subscribe('object', (evt) => seen.push(evt));
+      manager.subscribe('object', (evt) => { seen.push(evt); });
 
       await manager.bulkUnregister([
         { type: 'object', name: 'a' },
@@ -442,7 +443,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
       await manager.register('object', 'other', { name: 'other', packageId: 'com.other' }, { notify: false });
 
       const seen: any[] = [];
-      manager.subscribe('object', (evt) => seen.push(evt));
+      manager.subscribe('object', (evt) => { seen.push(evt); });
 
       await manager.unregisterPackage('com.acme.crm');
 
@@ -456,7 +457,7 @@ describe('#3112 — register()/unregister() notify subscribe() watchers', () =>
   describe('registerInMemory()', () => {
     it('stays silent by design (GitOps-owned artefacts, documented on the method)', async () => {
       const seen: any[] = [];
-      manager.subscribe('datasource', (evt) => seen.push(evt));
+      manager.subscribe('datasource', (evt) => { seen.push(evt); });
 
       manager.registerInMemory('datasource', 'crm_db', { name: 'crm_db', origin: 'code' });
 
diff --git a/packages/metadata/src/serializers/serializers.test.ts b/packages/metadata/src/serializers/serializers.test.ts
index 9533a416a1..3943092f54 100644
--- a/packages/metadata/src/serializers/serializers.test.ts
+++ b/packages/metadata/src/serializers/serializers.test.ts
@@ -1,7 +1,7 @@
 import { describe, it, expect } from 'vitest';
-import { JSONSerializer } from '../serializers/json-serializer';
-import { YAMLSerializer } from '../serializers/yaml-serializer';
-import { TypeScriptSerializer } from '../serializers/typescript-serializer';
+import { JSONSerializer } from '../serializers/json-serializer.js';
+import { YAMLSerializer } from '../serializers/yaml-serializer.js';
+import { TypeScriptSerializer } from '../serializers/typescript-serializer.js';
 
 describe('Serializers', () => {
   describe('JSONSerializer', () => {
diff --git a/packages/metadata/src/utils/lru-cache.test.ts b/packages/metadata/src/utils/lru-cache.test.ts
index cef0663218..53c521a78e 100644
--- a/packages/metadata/src/utils/lru-cache.test.ts
+++ b/packages/metadata/src/utils/lru-cache.test.ts
@@ -1,7 +1,7 @@
 // Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
 
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
-import { LRUCache } from './lru-cache';
+import { LRUCache } from './lru-cache.js';
 
 describe('LRUCache', () => {
   describe('basic set / get', () => {
diff --git a/scripts/check-type-check-coverage.mjs b/scripts/check-type-check-coverage.mjs
index 12fdaecc18..56433caaab 100644
--- a/scripts/check-type-check-coverage.mjs
+++ b/scripts/check-type-check-coverage.mjs
@@ -642,6 +642,27 @@ const ROOT_PROGRAM_COUPLED_SCRIPT = 'scripts/check-test-typecheck.mts';
 // at all, and simultaneously EXPOSED 12 real defects in `service-settings`
 // that the unresolved imports had been masking. A config-tier count is an
 // upper bound on nothing: fix the config first, then read the residue.
+//
+// `@objectstack/metadata` GRADUATED from this ledger (#14342; entry: 89 raw,
+// repaired to 0, the route #13978 took for `metadata-protocol` and ruled by
+// precedent for this one). It is worth a line because it is the sharpest
+// measurement of the paragraph directly above, and because the composition
+// this entry recorded was wrong in a way no re-measure could show. Its opening
+// itemisation read, verbatim, 'code-tier 30 (TS2345 x30); config-tier 25
+// (TS2835 x25); noise 34 (TS7006 x33, TS6133)'. Repairing the 25 TS2835 alone
+// took the pile to 52 -- ALL 33 TS7006 dissolved (they were the
+// cascade, not noise the package owed), while 20 TS2322 and 1 TS18048 appeared
+// that the 89 had never contained. So the true code tier was 51, not 30: 30
+// TS2345 (the one shared mock `PluginContext` literal, closed by adding the two
+// members it lacked to the single factory), 20 TS2322 (`(evt) => arr.push(evt)`
+// in a watcher slot typed `void | Promise<void>` -- a concise arrow body whose
+// `number` only becomes visible once the callback parameter has a real type,
+// and which the void-return assignability rule does NOT forgive because the
+// target is a union), and 1 TS18048. This is the `rest` lesson (TS18048 x13
+// exposed the same way) measured a second time, on a package whose note had
+// already itemised its own tiers with confidence: a tier split read off an
+// unrepaired config is a guess about what is UNDER it, and the only honest way
+// to size the code tier is to fix the config and look.
 const DEBT = {
   '@objectstack/cloud-connection': {
     errors: 13,
@@ -658,21 +679,6 @@ const DEBT = {
     errors: 3,
     note: 'all code-tier (TS2769/TS18046).',
   },
-  '@objectstack/metadata': {
-    errors: 89,
-    note: 'code-tier 30 (TS2345 x30); config-tier 25 (TS2835 x25); noise 34 (TS7006 x33, TS6133). '
-      + 'Re-measured 89 at 4b84834a32, DOWN from 92 at 5ab08428 -- itself up from 87, so this entry has '
-      + 'now drifted both ways. Against the composition recorded here at 92 the delta is attributable '
-      + 'tier by tier: code-tier lost the 4 TS2322 (-4), config-tier gained one TS2835 (+1), noise did '
-      + 'not move. TS2353 then TS2322 have each passed through the code tier and left; TS2345 x30 is its '
-      + 'only lasting resident. Read the 89 as three mechanical repairs, not 89 problems: all 30 TS2345 '
-      + 'are one defect thirty times over, in metadata.test.ts between 608 and 945, every one the same '
-      + 'mock PluginContext literal missing registerServiceFactory and getServiceScoped, so one shared '
-      + 'fixture closes the code tier outright; the 25 TS2835 are the widest spread (12 files) and are '
-      + 'one codemod, a relative import wanting an explicit .js extension under node16 resolution. '
-      + 'metadata.test.ts (34) and register-notifies-watchers.test.ts (16) do still hold 50 of the 89, '
-      + 'but that is over HALF -- the "two thirds" claimed here was true at neither 92 nor 89.',
-  },
   '@objectstack/observability': {
     errors: 11,
     note: 'all code-tier (TS2554 wrong arity x10, TS2552).',