fix(spec): the view-item D3 entry names the overlay pair as its own family

After #20255 landed, its view-item D3 entry still said a flattened overlay
keeps its own owner/hidden. The overlay pair is a separate family with its
own D2 view-overlay-owner-hidden-removed and D3 view-overlay-owner-hidden-retired.
The overlay pin now reads another entry naming the conversion as a
cross-reference that must point at this family's record.

Claude-Session: https://claude.ai/code/session_01CiCTczDo7tGhafXjf61dUJ
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

packages/spec/src/migrations/entries/semantic/18.view-item-owner-hidden-retired.ts

@@ -24,8 +24,9 @@ export const entry: SemanticMigration = {
     + 'A view an author marked as one user\'s, or hid from the switcher, has always been listed to '
     + 'every user who can read the object — its name, its columns, its filters and its sort. '
     + 'Whether anything in such a view was meant to stay private, and whether it should now be '
-    + 'deleted rather than kept, is the author\'s call. A flattened view overlay keeps its own '
-    + '`owner` and `hidden`: those live on a different door that this retirement does not touch.',
+    + 'deleted rather than kept, is the author\'s call. A flattened view overlay\'s own `owner` and '
+    + '`hidden` are a separate family on a different door, with their own D2 conversion '
+    + '`view-overlay-owner-hidden-removed` and their own D3 entry `view-overlay-owner-hidden-retired`.',
   acceptanceCriteria: 'No view item record in `views` or in an assembled artifact carries `owner` or '
     + '`hidden`; the parse refuses both by name, and an artifact assembled before the upgrade '
     + 'registers without a refusal over them. For every view that had carried either key, the '

packages/spec/src/migrations/registry.ts

@@ -15917,8 +15917,9 @@ const step18: MigrationStep = {
         + 'A view an author marked as one user\'s, or hid from the switcher, has always been listed to '
         + 'every user who can read the object — its name, its columns, its filters and its sort. '
         + 'Whether anything in such a view was meant to stay private, and whether it should now be '
-        + 'deleted rather than kept, is the author\'s call. A flattened view overlay keeps its own '
-        + '`owner` and `hidden`: those live on a different door that this retirement does not touch.',
+        + 'deleted rather than kept, is the author\'s call. A flattened view overlay\'s own `owner` and '
+        + '`hidden` are a separate family on a different door, with their own D2 conversion '
+        + '`view-overlay-owner-hidden-removed` and their own D3 entry `view-overlay-owner-hidden-retired`.',
       acceptanceCriteria: 'No view item record in `views` or in an assembled artifact carries `owner` or '
         + '`hidden`; the parse refuses both by name, and an artifact assembled before the upgrade '
         + 'registers without a refusal over them. For every view that had carried either key, the '

packages/spec/src/ui/view-overlay-owner-hidden-retirement.test.ts

@@ -343,8 +343,14 @@ describe('overlay owner/hidden retirement — ADR-0087 registration', () => {
     expect(entry.reason).toContain('Measured writers in this repository and its sibling UI: zero');
     expect(entry.reason).toContain('NOT MEASURED');
     expect(entry.acceptanceCriteria.length).toBeGreaterThan(0);
-    // One family, one record: no other entry of the step claims this conversion.
-    const claimants = semantic.filter((s) => JSON.stringify(s).includes('view-overlay-owner-hidden-removed'));
-    expect(claimants.map((s) => s.id)).toEqual(['view-overlay-owner-hidden-retired']);
+    // One family, one record. Another entry may NAME this conversion only as a
+    // cross-reference that points at this record (the view item family's D3
+    // entry does, to say the overlay pair is a separate family) — never as a
+    // second record of its own.
+    const naming = semantic.filter((s) => JSON.stringify(s).includes('view-overlay-owner-hidden-removed'));
+    expect(naming.map((s) => s.id)).toContain('view-overlay-owner-hidden-retired');
+    for (const other of naming.filter((s) => s.id !== 'view-overlay-owner-hidden-retired')) {
+      expect(JSON.stringify(other), other.id).toContain('view-overlay-owner-hidden-retired');
+    }
   });
 });