@@ -0,0 +1,88 @@
+---
+"@objectstack/spec": minor
+---
+
+feat(spec)!: `FileValue.duration` and `CompatibilityMatrixEntry.estimatedMigrationTime` carry their unit in the key name (#18669, ruling A)
+
+<!-- adr-0087: registered data-file-value-duration-unit-in-key, kernel-compatibility-matrix-estimated-migration-time-unit-in-key -->
+
+**BREAKING** — two duration-shaped `z.number()` keys are renamed. No value type moves, no key is
+removed from the contract, and nothing already stored is narrowed.
+
+| def | before | after |
+|:--|:--|:--|
+| `data/FileValue` | `duration: 12` | `durationSeconds: 12` |
+| `kernel/CompatibilityMatrixEntry` | `estimatedMigrationTime: 8` | `estimatedMigrationTimeHours: 8` |
+
+Maintainer ruling A on #18669 (2026-09-17, decision batch #151 item 4): rename each key, with an
+ADR-0087 conversion-layer entry each — ⛔ no new closed type, ⛔ no narrowing of stored data.
+
+## Why each bare name was worth a rename
+
+`FileValue.duration` declared its unit in **no channel at all** — no `.describe()`, no JSDoc, no
+unit token in the key — so the published reference page printed a bare number and the authoring
+site printed nothing. The company it kept is what makes it a trap rather than an omission: the
+only other number on `FileValue` is `size`, a **byte** count, so the one member that measured
+time was indistinguishable from a count at the site an author (very often a model, ADR-0033)
+writes it.
+
+`CompatibilityMatrixEntry.estimatedMigrationTime` said *"Estimated migration time in hours"* in a
+source **JSDoc** and carried no `.describe()` — the #15939 shape, one def over. The JSDoc stops at
+the source file; `.describe()` is what `content/docs/references/**` renders, so the published page
+printed a bare number directly beside `migrationComplexity`, whose scale *is* named
+(`trivial`/`simple`/`moderate`/`complex`/`major`). A reader comparing `major` with `40` could not
+tell minutes from hours from days.
+
+## What an author must change
+
+Rename the key. **Nothing else** — both values keep the type they had.
+
+```diff
+  // an expanded file/image/avatar/video/audio value
+  {
+    url: 'https://cdn.example.com/files/clip.mp4',
+-   duration: 12.34,
++   durationSeconds: 12.34,
+  }
+
+  // a plugin compatibility-matrix entry
+  {
+    from: '1.9.0', to: '2.0.0', compatibility: 'breaking-changes',
+-   estimatedMigrationTime: 8,
++   estimatedMigrationTimeHours: 8,
+  }
+```
+
+## Deliberately NOT narrowed
+
+Both keys stay `z.number().optional()`. `durationSeconds: 12.34` still parses — a fractional
+second is the ordinary shape of a media length — so the closed `DurationSeconds` type
+(`z.number().int().nonnegative()`, #18122) was **refused** by the ruling, and so was a bare
+`.int()`. `FileValue` is one of the six rows #18122 derived its unit set from; it is the one that
+takes a **name** instead of a type. `estimatedMigrationTimeHours` keeps `hours` rather than
+converting to seconds, for the same reason: the value does not move.
+
+The hours key also gains `.describe('Estimated migration time in hours')`, and that half is not
+cosmetic — renaming alone would leave the key name and a source comment agreeing about a unit the
+published page does not print, which `check:duration-unit-keys` refuses as
+`unit-in-jsdoc-not-in-describe` (ruled an offence 2026-09-18, decision batch #158 item 5, letter
+A). `FileValue.durationSeconds` gains `.describe('Media duration in seconds')` for the same
+reader.
+
+## The kit
+
+- a `retiredKey()` tombstone on each old spelling, so `tsc` types it `never` and a value reaching
+  the parse raises the **rename prescription** instead of vanishing. Neither enclosing shape is
+  `.strict()`: `CompatibilityMatrixEntrySchema` is a plain `z.object` and would have stripped the
+  old spelling in silence, and `FileValueSchema` is the one deliberate `z.looseObject` in
+  `field-value.zod.ts` and would have waved it through as an unrecognised extra
+- two ADR-0087 D3 semantic entries and two `RETIRED_KEYS_BY_MAJOR[18]` rows. **No D2 conversion**
+  for either: `FileValueSchema` is the ADR-0104 D3 wave-2 *expanded read* form, derived at read
+  time from a `sys_file` id (the stored form is `FileReferenceIdValueSchema`, an opaque string),
+  and a plugin compatibility matrix is a published version manifest that `stack.zod.ts` declares
+  no collection of — neither is ever a stored `sys_metadata` row, so the chain has no seam that
+  would see one
+- both authorable-surface rows move: each becomes `<key> [RETIRED]` beside its renamed row, since
+  both are **top-level** properties of their def
+
+Clause-②: yes
@@ -1161,7 +1161,7 @@ media metadata object, whose only required member is `url`:
 }
 ```
 
-`alt` and `duration` are the other optional members. The keys are `name` and
+`alt` and `durationSeconds` are the other optional members. The keys are `name` and
 `mimeType` — not `filename` / `content_type`.
 
 <Callout>
 
@@ -120,7 +120,8 @@ Type: `string`
 | **size** | `number` | optional |  |
 | **mimeType** | `string` | optional |  |
 | **alt** | `string` | optional |  |
-| **duration** | `number` | optional |  |
+| **durationSeconds** | `number` | optional | Media duration in seconds |
+| **duration** | `never` | optional | [REMOVED] `FileValue.duration` was renamed to `durationSeconds` in @objectstack/spec 17 — the unit of a duration-shaped number lives in the key name, not only in the describe prose. Rename the key to `durationSeconds`; the value (seconds) is unchanged, and a fractional second is still legal. |
 
 ---
 
@@ -145,7 +146,8 @@ Type: `string`
 | **size** | `number` | optional |  |
 | **mimeType** | `string` | optional |  |
 | **alt** | `string` | optional |  |
-| **duration** | `number` | optional |  |
+| **durationSeconds** | `number` | optional | Media duration in seconds |
+| **duration** | `never` | optional | [REMOVED] `FileValue.duration` was renamed to `durationSeconds` in @objectstack/spec 17 — the unit of a duration-shaped number lives in the key name, not only in the describe prose. Rename the key to `durationSeconds`; the value (seconds) is unchanged, and a fractional second is still legal. |
 
 
 ---
 
@@ -77,7 +77,8 @@ Compatibility level between versions
 | **breakingChanges** | `{ introducedIn: string; type: Enum<'api-removed' \| 'api-renamed' \| 'api-signature-changed' \| 'behavior-changed' \| …>; description: string; migrationGuide?: string; … }[]` | optional |  |
 | **migrationRequired** | `boolean` | optional (default: `false`) |  |
 | **migrationComplexity** | `Enum<'trivial' \| 'simple' \| 'moderate' \| 'complex' \| 'major'>` | optional |  |
-| **estimatedMigrationTime** | `number` | optional |  |
+| **estimatedMigrationTimeHours** | `number` | optional | Estimated migration time in hours |
+| **estimatedMigrationTime** | `never` | optional | [REMOVED] `CompatibilityMatrixEntry.estimatedMigrationTime` was renamed to `estimatedMigrationTimeHours` in @objectstack/spec 17 — the unit of a duration-shaped number lives in the key name, not only in prose. Rename the key to `estimatedMigrationTimeHours`; the value (hours) is unchanged. |
 | **migrationScript** | `string` | optional | Path to migration script |
 | **testCoverage** | `number` | optional | Percentage of migration covered by tests |
 
@@ -191,7 +192,8 @@ Compatibility level between versions
 | **breakingChanges** | `{ introducedIn: string; type: Enum<'api-removed' \| 'api-renamed' \| 'api-signature-changed' \| 'behavior-changed' \| …>; description: string; migrationGuide?: string; … }[]` | optional |  |
 | **migrationRequired** | `boolean` | optional (default: `false`) |  |
 | **migrationComplexity** | `Enum<'trivial' \| 'simple' \| 'moderate' \| 'complex' \| 'major'>` | optional |  |
-| **estimatedMigrationTime** | `number` | optional |  |
+| **estimatedMigrationTimeHours** | `number` | optional | Estimated migration time in hours |
+| **estimatedMigrationTime** | `never` | optional | [REMOVED] `CompatibilityMatrixEntry.estimatedMigrationTime` was renamed to `estimatedMigrationTimeHours` in @objectstack/spec 17 — the unit of a duration-shaped number lives in the key name, not only in prose. Rename the key to `estimatedMigrationTimeHours`; the value (hours) is unchanged. |
 | **migrationScript** | `string` | optional | Path to migration script |
 | **testCoverage** | `number` | optional | Percentage of migration covered by tests |
 
@@ -285,7 +287,8 @@ Compatibility level between versions
 | **breakingChanges** | `{ introducedIn: string; type: Enum<'api-removed' \| 'api-renamed' \| 'api-signature-changed' \| 'behavior-changed' \| …>; description: string; migrationGuide?: string; … }[]` | optional |  |
 | **migrationRequired** | `boolean` | optional (default: `false`) |  |
 | **migrationComplexity** | `Enum<'trivial' \| 'simple' \| 'moderate' \| 'complex' \| 'major'>` | optional |  |
-| **estimatedMigrationTime** | `number` | optional |  |
+| **estimatedMigrationTimeHours** | `number` | optional | Estimated migration time in hours |
+| **estimatedMigrationTime** | `never` | optional | [REMOVED] `CompatibilityMatrixEntry.estimatedMigrationTime` was renamed to `estimatedMigrationTimeHours` in @objectstack/spec 17 — the unit of a duration-shaped number lives in the key name, not only in prose. Rename the key to `estimatedMigrationTimeHours`; the value (hours) is unchanged. |
 | **migrationScript** | `string` | optional | Path to migration script |
 | **testCoverage** | `number` | optional | Percentage of migration covered by tests |
 
 
@@ -119,17 +119,17 @@ describe('SqlDriver scalar type fidelity (rating/slider/toggle/progress)', () =>
         id: 'z4',
         name: 'D',
         f_record: { home: '+1', work: '+2' },
-        f_video: { url: 'https://cdn/v.mp4', duration: 12 },
-        f_audio: { url: 'https://cdn/a.mp3', duration: 30 },
+        f_video: { url: 'https://cdn/v.mp4', durationSeconds: 12 },
+        f_audio: { url: 'https://cdn/a.mp3', durationSeconds: 30 },
       },
       { bypassTenantAudit: true },
     );
     const row = await driver.findOne('zoo', { where: { id: 'z4' } }, { bypassTenantAudit: true });
     assert(row !== null, 'findOne answered the not-found arm for a seeded id');
 
     expect(row.f_record).toEqual({ home: '+1', work: '+2' });
-    expect(row.f_video).toEqual({ url: 'https://cdn/v.mp4', duration: 12 });
-    expect(row.f_audio).toEqual({ url: 'https://cdn/a.mp3', duration: 30 });
+    expect(row.f_video).toEqual({ url: 'https://cdn/v.mp4', durationSeconds: 12 });
+    expect(row.f_audio).toEqual({ url: 'https://cdn/a.mp3', durationSeconds: 30 });
   });
 });
 
 
@@ -443,7 +443,8 @@
     "data/FilePersistenceConfig:path",
     "data/FilePersistenceConfig:type",
     "data/FileValue:alt",
-    "data/FileValue:duration",
+    "data/FileValue:duration [RETIRED]",
+    "data/FileValue:durationSeconds",
     "data/FileValue:mimeType",
     "data/FileValue:name",
     "data/FileValue:size",
 
@@ -30,7 +30,8 @@
     "kernel/ClusterCapabilityConfig:useExistingPool",
     "kernel/CompatibilityMatrixEntry:breakingChanges",
     "kernel/CompatibilityMatrixEntry:compatibility",
-    "kernel/CompatibilityMatrixEntry:estimatedMigrationTime",
+    "kernel/CompatibilityMatrixEntry:estimatedMigrationTime [RETIRED]",
+    "kernel/CompatibilityMatrixEntry:estimatedMigrationTimeHours",
     "kernel/CompatibilityMatrixEntry:from",
     "kernel/CompatibilityMatrixEntry:migrationComplexity",
     "kernel/CompatibilityMatrixEntry:migrationRequired",
 
@@ -359,7 +359,20 @@ describe('valueSchemaFor — stored form (field-zoo reality)', () => {
       bad({ type }, { name: 'x' }, 'expanded');   // object without url — the tightening
       bad({ type }, { size: 10 }, 'expanded');    // ditto
     }
-    ok({ type: 'video' }, { url: 'https://cdn/v.mp4', duration: 12 }, 'expanded');
+    ok({ type: 'video' }, { url: 'https://cdn/v.mp4', durationSeconds: 12 }, 'expanded');
+    // #18669 ruling A: the rename carries NO narrowing, so a fractional second
+    // — the ordinary shape of a media length — is still legal. A closed
+    // `DurationSeconds` (`.int().nonnegative()`) would have refused this, which
+    // is why the ruling declined one.
+    ok({ type: 'video' }, { url: 'https://cdn/v.mp4', durationSeconds: 12.34 }, 'expanded');
+    // The retired spelling is refused with the rename prescription, not with a
+    // bare unrecognized-key error — and on a `looseObject` a bare deletion
+    // would have waved it through as an extra key instead.
+    const retiredDuration = valueSchemaFor({ type: 'video' }, 'expanded')
+      .safeParse({ url: 'https://cdn/v.mp4', duration: 12 });
+    expect(retiredDuration.success).toBe(false);
+    expect(JSON.stringify((retiredDuration as { error: unknown }).error))
+      .toContain('Rename the key to `durationSeconds`');
   });
 
   it('structured JSON types', () => {
 
@@ -40,6 +40,7 @@ import { lazySchema } from '../shared/lazy-schema';
 // `strictObjectError`, `declarationStore`), and the error map builds its
 // suggester lazily on the first ISSUE, never at module scope. Measured with
 // this file as the entry module under eager evaluation (#13802).
+import { retiredKey } from '../shared/retired-key';
 import { strictObject } from '../shared/strict-object';
 import { SystemObjectName } from '../system/constants/system-names';
 import type { FieldType } from './field.zod';
@@ -496,7 +497,25 @@ export const FileValueSchema = lazySchema(() => z.looseObject({
   size: z.number().optional(),
   mimeType: z.string().optional(),
   alt: z.string().optional(),
-  duration: z.number().optional(),
+
+  // Renamed from `duration` (#18669, ruling A, decision batch #151 item 4): the
+  // unit of a duration-shaped number lives in the key NAME, not only in prose.
+  // The company it kept is what made the bare name worth a rename — the only
+  // other number on this shape is `size`, a BYTE count, so the one member that
+  // measured time was indistinguishable from a count at the authoring site, and
+  // a media length is exactly the value an author guesses at 1000x stakes.
+  // ⛔ The value type is deliberately unchanged: a fractional second is a legal
+  // media length (`12.34`), so no closed `DurationSeconds` and no `.int()`
+  // floor rides along with the rename.
+  durationSeconds: z.number().optional().describe('Media duration in seconds'),
+
+  /** Tombstone for the rename above (#18669, ruling A, decision batch #151 item 4). */
+  duration: retiredKey(
+    '`FileValue.duration` was renamed to `durationSeconds` in @objectstack/spec 17 — '
+    + 'the unit of a duration-shaped number lives in the key name, not only in the describe '
+    + 'prose. Rename the key to `durationSeconds`; the value (seconds) is unchanged, and a '
+    + 'fractional second is still legal.',
+  ),
 }));
 export type FileValue = z.input<typeof FileValueSchema>;
 
 
@@ -166,14 +166,53 @@ describe('Plugin Versioning Schemas', () => {
         ],
         migrationRequired: true,
         migrationComplexity: 'moderate' as const,
-        estimatedMigrationTime: 8,
+        estimatedMigrationTimeHours: 8,
         migrationScript: './scripts/migrate-v1-to-v2.ts',
         testCoverage: 95,
       };
       const result = CompatibilityMatrixEntrySchema.parse(entry);
       expect(result.compatibility).toBe('breaking-changes');
       expect(result.migrationRequired).toBe(true);
-      expect(result.estimatedMigrationTime).toBe(8);
+      expect(result.estimatedMigrationTimeHours).toBe(8);
+    });
+
+    // #18669 ruling A. The rename above is only half the contract; this is the
+    // other half. Without it the retirement is pinned by nothing: this shape is
+    // a plain `z.object`, so deleting the key rather than tombstoning it would
+    // strip the old spelling in SILENCE and every assertion above would stay
+    // green. The pin is on the PRESCRIPTION, not on "it throws" — a bare
+    // unrecognized-key error would also throw, and would carry no rename.
+    // Asserted the way `rollout.duration`'s pin below already asserts it: the
+    // issue is looked up BY PATH and its `code` is read, so a refusal that
+    // arrived as a bare `unrecognized_keys` cannot satisfy this by happening to
+    // mention the key name somewhere in the envelope.
+    it('REFUSES the retired `estimatedMigrationTime` with the rename in the message', () => {
+      const result = CompatibilityMatrixEntrySchema.safeParse({
+        from: '1.0.0',
+        to: '2.0.0',
+        compatibility: 'breaking-changes',
+        estimatedMigrationTime: 8,
+      });
+      expect(result.success).toBe(false);
+      const issue = result.error!.issues.find((i) => i.path.join('.') === 'estimatedMigrationTime');
+      expect(issue).toBeDefined();
+      expect(issue!.code).not.toBe('unrecognized_keys');
+      expect(issue!.message).toContain(
+        '`CompatibilityMatrixEntry.estimatedMigrationTime` was renamed to `estimatedMigrationTimeHours`',
+      );
+    });
+
+    // The no-narrowing half of the same ruling: the value type did not move, so
+    // a fractional estimate that parsed before still parses. A sweep that added
+    // `.int()` or adopted a closed duration type turns this red.
+    it('keeps the value type: a fractional hours estimate still parses', () => {
+      const parsed = CompatibilityMatrixEntrySchema.parse({
+        from: '1.0.0',
+        to: '2.0.0',
+        compatibility: 'breaking-changes',
+        estimatedMigrationTimeHours: 8.5,
+      });
+      expect(parsed.estimatedMigrationTimeHours).toBe(8.5);
     });
   });
 
@@ -421,7 +460,7 @@ describe('Plugin Versioning Schemas', () => {
         ],
         migrationRequired: true,
         migrationComplexity: 'major',
-        estimatedMigrationTime: 40,
+        estimatedMigrationTimeHours: 40,
       });
       expect(matrixEntry.migrationRequired).toBe(true);
       expect(matrixEntry.migrationComplexity).toBe('major');
Original file line number	Diff line number	Diff line change
@@ -1161,7 +1161,7 @@ media metadata object, whose only required member is `url`:
`1161`	`1161`	`}`
`1162`	`1162`	```
`1163`	`1163`
`1164`		-`alt` and `duration` are the other optional members. The keys are `name` and
	`1164`	+`alt` and `durationSeconds` are the other optional members. The keys are `name` and
`1165`	`1165`	`mimeType` — not `filename` / `content_type`.
`1166`	`1166`
`1167`	`1167`	`<Callout>`