docs(spec): say what is true about the readers of a list view's tabs

A list view's own `tabs` has no reader, and objectui's TabBar, the one
component that would draw it, has zero production mounts. The earlier wording
said the one component that reads a ViewTab[] has none, which is false:
`userFilters.tabs` is a ViewTab[] too, and TabFilters reads and renders it.
The population sentence now says examples or platform sources, and that the
one published skill example that taught the key is corrected in this change.
Corrected in the changeset, the tombstone docblock, both retired-key entries,
the conversion docblock, the step-18 rationale, the ledger note and the pin's
header; the migration registry regenerated.

Claude-Session: https://claude.ai/code/session_01QcAS3qiYYZNezaxZxaUdMV
Co-Authored-By: Claude <noreply@anthropic.com>

Author: claude

.changeset/list-view-tabs-retired.md

@@ -12,13 +12,16 @@ enforce-or-remove; triage verdict RETIRE, on the rule that a capability the
 mainstream has and this platform already delivers keeps ONE spelling.
 
 The key parsed at every list-view door and was stored, and no renderer ever
-drew it. Measured before removal, each reading beside a lit control: the one
-component that reads a `ViewTab[]` (objectui's `TabBar`) has zero production
-mounts at the objectui commit this repo pins — every occurrence is in its own
-two test files — while the saved-view switcher (`ViewTabBar`) mounts in the
-object view and is fed from the object's `listViews`. That switcher IS the tab
-strip above an object's records: one tab per named list view. Zero list views
-in this repo's examples, skills or platform sources authored the key.
+drew it. Measured before removal, each reading beside a lit control: a list
+view's own `tabs` has no reader, and objectui's `TabBar` — the one component
+that would draw it — has zero production mounts at the objectui commit this
+repo pins (every occurrence is in its own two test files), while the saved-view
+switcher (`ViewTabBar`) mounts in the object view and is fed from the object's
+`listViews`. That switcher IS the tab strip above an object's records: one tab
+per named list view. `userFilters.tabs` is a different key with the same
+element type: it is read and rendered as a page list's preset bar, and it
+stays. Zero list views in this repo's examples or platform sources authored the
+key; the one published skill example that taught it is corrected here.
 
 ### FROM → TO
 

packages/spec/liveness/view.json

@@ -211,7 +211,7 @@
           "status": "dead",
           "verifiedAt": "2026-09-27",
           "evidenceScope": "cross-repo",
-          "note": "REMOVED 2026-09-27 (#20301, ADR-0049 enforce-or-remove; triage verdict RETIRE under the maintainer's #18900 criterion — mainstream named-view switching is already delivered here, by `listViews` rendered in ViewTabBar) — tombstoned at the schema (retiredKey carries the prescription; authoring it is a tsc error and a parse error at every list-view door built from the shape: ListViewSchema, ObjectListViewSchema and the flattened overlay arm) and stripped from stored rows and sources by the protocol-18 view-list-tabs-removed conversion. The entry stays because retiredKey keeps the key in the walked shape (the rls.priority precedent); to give end users one tab per preset, declare each tab as a named entry under the object's `listViews` — every entry renders as a tab in the saved-view switcher. RE-MEASURED 2026-09-27 before removal, with lit controls: objectui at the pinned sha f8a9d0fb — every `<TabBar` occurrence is in one of its two test files (components/__tests__/TabBar.i18nLabel.test.tsx, __tests__/icon-seam-fallbacks-5935.test.tsx) and every TabBar import is a test's, zero production mounts; CONTROL on the same instrument: `<ViewTabBar` mounts at app-shell/src/views/ObjectView.tsx, fed `views={viewTabItems}` built from `objectDef.listViews`. objectui's own type mirror (types/src/objectql.ts, `tabs?: ListViewSchema['tabs']`, and the zod twin's by-reference import) carries the tombstone in on the pin bump, the pageName precedent. In this repo: zero authorings in examples/, skills/ (one published rules example taught the key and is corrected in the same change) or platform sources — CONTROL: `listViews:` authored in 9 example files. The two author-time reference walks (packages/lint/src/validate-list-view-field-refs.ts#checkTabs, packages/metadata-protocol/src/metadata-diagnostics.ts) read raw input, deliver no tab bar, and are left for their own follow-up. The prior note (RE-DERIVED 2026-09-07, #16362) flipped this row live to dead on the same measurement at objectui @a472b071 and recorded that TabBar does sort on `tabs[].order` — both moot now that the key is gone and nothing mounts TabBar."
+          "note": "REMOVED 2026-09-27 (#20301, ADR-0049 enforce-or-remove; triage verdict RETIRE under the maintainer's #18900 criterion — mainstream named-view switching is already delivered here, by `listViews` rendered in ViewTabBar) — tombstoned at the schema (retiredKey carries the prescription; authoring it is a tsc error and a parse error at every list-view door built from the shape: ListViewSchema, ObjectListViewSchema and the flattened overlay arm) and stripped from stored rows and sources by the protocol-18 view-list-tabs-removed conversion. The entry stays because retiredKey keeps the key in the walked shape (the rls.priority precedent); to give end users one tab per preset, declare each tab as a named entry under the object's `listViews` — every entry renders as a tab in the saved-view switcher. RE-MEASURED 2026-09-27 before removal, with lit controls: objectui at the pinned sha f8a9d0fb — every `<TabBar` occurrence is in one of its two test files (components/__tests__/TabBar.i18nLabel.test.tsx, __tests__/icon-seam-fallbacks-5935.test.tsx) and every TabBar import is a test's, zero production mounts (TabBar is the one component that would draw a list view's own `tabs`; `userFilters.tabs`, a different key of the same element type, is read and rendered by UserFilters/TabFilters and stays); CONTROL on the same instrument: `<ViewTabBar` mounts at app-shell/src/views/ObjectView.tsx, fed `views={viewTabItems}` built from `objectDef.listViews`. objectui's own type mirror (types/src/objectql.ts, `tabs?: ListViewSchema['tabs']`, and the zod twin's by-reference import) carries the tombstone in on the pin bump, the pageName precedent. In this repo: zero authorings in examples/ or platform sources — CONTROL: `listViews:` authored in 9 example files; the one published skill example that taught it (skills/objectstack-ui/rules/list-views.md) is corrected in the same change. The two author-time reference walks (packages/lint/src/validate-list-view-field-refs.ts#checkTabs, packages/metadata-protocol/src/metadata-diagnostics.ts) read raw input, deliver no tab bar, and are left for their own follow-up. The prior note (RE-DERIVED 2026-09-07, #16362) flipped this row live to dead on the same measurement at objectui @a472b071 and recorded that TabBar does sort on `tabs[].order` — both moot now that the key is gone and nothing mounts TabBar."
         },
         "addRecord": {
           "status": "live",

packages/spec/src/conversions/registry.ts

@@ -10572,12 +10572,14 @@ const viewOverlayOwnerHiddenRemoved: MetadataConversion = {
  * maintainer's #18900 criterion: mainstream named-view switching is already
  * delivered here, by `listViews`).
  *
- * `ListViewSchema.tabs` parsed, was stored, and drew nothing. The one
- * component that reads a `ViewTab[]` — objectui's `TabBar` — has zero
- * production mounts at the pinned objectui sha, and the tab strip above an
- * object's records is the saved-view switcher (`ViewTabBar`), which renders
- * one tab per NAMED LIST VIEW and reads no `tabs` key. The measurement, with
- * lit controls, is on the ledger row (`liveness/view.json`,
+ * `ListViewSchema.tabs` parsed, was stored, and drew nothing. A list view's
+ * own `tabs` has no reader, and objectui's `TabBar` — the one component that
+ * would draw it — has zero production mounts at the pinned objectui sha. The
+ * tab strip above an object's records is the saved-view switcher
+ * (`ViewTabBar`), which renders one tab per NAMED LIST VIEW and reads no `tabs`
+ * key. `userFilters.tabs`, a different key of the same element type, is read
+ * and rendered (the page preset bar) and stays. The measurement, with lit
+ * controls, is on the ledger row (`liveness/view.json`,
  * `/props/list/children/tabs`).
  *
  * **Retired from the load path** — the key is a `retiredKey()` tombstone on the
@@ -10587,9 +10589,9 @@ const viewOverlayOwnerHiddenRemoved: MetadataConversion = {
  * stored `view` row CAN carry the key: every list-view door accepted and
  * persisted it until this release, and `applyConversionsToStoredItem` replays
  * the chain over stored `view` rows as `{ views: [row] }`. Without it such a
- * row would fail its rehydration parse over a key that never had an effect. It
- * also lets `os migrate meta --from 17` list the mechanical edits for existing
- * sources.
+ * row would carry the retired key back to the strict write door, which refuses
+ * it on the next save, over a key that never had an effect. It also lets
+ * `os migrate meta --from 17` list the mechanical edits for existing sources.
  *
  * The delete is lossless in pixels: no renderer ever drew the tabs, so
  * removing them changes no screen. `stripKeys` deletion is idempotent by
@@ -10601,9 +10603,10 @@ const viewOverlayOwnerHiddenRemoved: MetadataConversion = {
  * and `view-export-options-pdf-removed` have. `objects[].listViews.*` is NOT
  * reached by any conversion in this registry, so an object body carrying the
  * key is refused at its own door rather than converted. Measured population
- * for both: zero authored list-view `tabs` in this tree's examples, skills and
- * platform sources (the in-tree hits are test fixtures of two author-time
- * reference walks, which read raw input and never parse it).
+ * for both: zero authored list-view `tabs` in this tree's examples or platform
+ * sources (the in-tree hits are test fixtures of two author-time reference
+ * walks, which read raw input and never parse it); the one published skill
+ * example that taught it is corrected in the same change.
  */
 const viewListTabsRemoved: MetadataConversion = {
   id: 'view-list-tabs-removed',

packages/spec/src/migrations/entries/retired-keys/18.ui__ListView__tabs.ts

@@ -2,11 +2,13 @@
 
 // #20301 (ADR-0049 enforce-or-remove; triage verdict RETIRE under the
 // maintainer's #18900 criterion). `ListView.tabs` declared tab definitions for
-// a multi-tab view interface, and no renderer ever drew them: the one
-// component that reads a `ViewTab[]` (objectui's `TabBar`) has no production
-// mount, and the tab strip above an object's records is the saved-view
-// switcher (`ViewTabBar`), which renders one tab per `listViews` entry and
-// reads no `tabs` key. Tombstoned with `retiredKey()` beside the `pageName`
-// tombstone already on this shape; `ViewTabSchema` stays, reused by the
-// page-only `userFilters.tabs` preset bar. D2: `view-list-tabs-removed`.
+// a multi-tab view interface, and no renderer ever drew them: a list view's own
+// `tabs` has no reader, and objectui's `TabBar`, the one component that would
+// draw it, has no production mount. The tab strip above an object's records is
+// the saved-view switcher (`ViewTabBar`), which renders one tab per `listViews`
+// entry and reads no `tabs` key. `userFilters.tabs`, a different key of the
+// same element type, is read and rendered, and stays. Tombstoned with
+// `retiredKey()` beside the `pageName` tombstone already on this shape;
+// `ViewTabSchema` stays, reused by the page-only `userFilters.tabs` preset bar.
+// D2: `view-list-tabs-removed`.
 export const entry = 'ui/ListView:tabs';

packages/spec/src/migrations/entries/retired-keys/18.ui__ObjectListView__tabs.ts

@@ -1,12 +1,14 @@
 // Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
 
 // #20301 (ADR-0049 enforce-or-remove; triage verdict RETIRE under the
-// maintainer's #18900 criterion). `ObjectListView.tabs` declared tab definitions for
-// a multi-tab view interface, and no renderer ever drew them: the one
-// component that reads a `ViewTab[]` (objectui's `TabBar`) has no production
-// mount, and the tab strip above an object's records is the saved-view
-// switcher (`ViewTabBar`), which renders one tab per `listViews` entry and
-// reads no `tabs` key. Tombstoned with `retiredKey()` beside the `pageName`
-// tombstone already on this shape; `ViewTabSchema` stays, reused by the
-// page-only `userFilters.tabs` preset bar. D2: `view-list-tabs-removed`.
+// maintainer's #18900 criterion). `ObjectListView.tabs` declared tab
+// definitions for a multi-tab view interface, and no renderer ever drew them: a
+// list view's own `tabs` has no reader, and objectui's `TabBar`, the one
+// component that would draw it, has no production mount. The tab strip above an
+// object's records is the saved-view switcher (`ViewTabBar`), which renders one
+// tab per `listViews` entry and reads no `tabs` key. `userFilters.tabs`, a
+// different key of the same element type, is read and rendered, and stays.
+// Tombstoned with `retiredKey()` beside the `pageName` tombstone already on
+// this shape; `ViewTabSchema` stays, reused by the page-only `userFilters.tabs`
+// preset bar. D2: `view-list-tabs-removed`.
 export const entry = 'ui/ObjectListView:tabs';

packages/spec/src/migrations/registry.ts

@@ -5406,10 +5406,12 @@ const step18: MigrationStep = {
     + 'built artifacts carry it without anyone having written it. Retired from the load path; '
     + 'an authored key is refused with the prescription. '
     + 'It also retires the list view\'s own `tabs` (ADR-0049 enforce-or-remove). The '
-    + 'key parsed and was stored at every list-view door and drew nothing: the one component '
-    + 'that reads a `ViewTab[]` has no production mount, and the tab strip above an object\'s '
-    + 'records is the saved-view switcher, which renders one tab per `listViews` entry and '
-    + 'reads no `tabs` key. The key is a `retiredKey()` tombstone on the list-view shape (its '
+    + 'key parsed and was stored at every list-view door and drew nothing: a list view\'s own '
+    + '`tabs` has no reader, the one component that would draw it has no production mount, '
+    + 'and the tab strip above an object\'s records is the saved-view switcher, which renders '
+    + 'one tab per `listViews` entry and reads no `tabs` key (`userFilters.tabs`, a different '
+    + 'key of the same element type, is read and rendered, and stays). The key is a '
+    + '`retiredKey()` tombstone on the list-view shape (its '
     + 'prescription says how to move each tab to a named `listViews` entry); `ViewTabSchema` '
     + 'itself stays, because the page-only `userFilters.tabs` preset bar reuses it and renders. '
     + 'The D2 conversion `view-list-tabs-removed` strips the key from every list payload in '
@@ -20274,13 +20276,15 @@ export const RETIRED_KEYS_BY_MAJOR: Readonly<Record<number, readonly string[]>>
     'ui/ListView:pageName',
     // #20301 (ADR-0049 enforce-or-remove; triage verdict RETIRE under the
     // maintainer's #18900 criterion). `ListView.tabs` declared tab definitions for
-    // a multi-tab view interface, and no renderer ever drew them: the one
-    // component that reads a `ViewTab[]` (objectui's `TabBar`) has no production
-    // mount, and the tab strip above an object's records is the saved-view
-    // switcher (`ViewTabBar`), which renders one tab per `listViews` entry and
-    // reads no `tabs` key. Tombstoned with `retiredKey()` beside the `pageName`
-    // tombstone already on this shape; `ViewTabSchema` stays, reused by the
-    // page-only `userFilters.tabs` preset bar. D2: `view-list-tabs-removed`.
+    // a multi-tab view interface, and no renderer ever drew them: a list view's own
+    // `tabs` has no reader, and objectui's `TabBar`, the one component that would
+    // draw it, has no production mount. The tab strip above an object's records is
+    // the saved-view switcher (`ViewTabBar`), which renders one tab per `listViews`
+    // entry and reads no `tabs` key. `userFilters.tabs`, a different key of the
+    // same element type, is read and rendered, and stays. Tombstoned with
+    // `retiredKey()` beside the `pageName` tombstone already on this shape;
+    // `ViewTabSchema` stays, reused by the page-only `userFilters.tabs` preset bar.
+    // D2: `view-list-tabs-removed`.
     'ui/ListView:tabs',
     // #16885 — the list view's `navigation.view` binding, retired under ADR-0049
     // enforce-or-remove by maintainer ruling 2026-09-13 (director decision batch
@@ -20368,14 +20372,16 @@ export const RETIRED_KEYS_BY_MAJOR: Readonly<Record<number, readonly string[]>>
     // `view-page-mount-removed`.
     'ui/ObjectListView:pageName',
     // #20301 (ADR-0049 enforce-or-remove; triage verdict RETIRE under the
-    // maintainer's #18900 criterion). `ObjectListView.tabs` declared tab definitions for
-    // a multi-tab view interface, and no renderer ever drew them: the one
-    // component that reads a `ViewTab[]` (objectui's `TabBar`) has no production
-    // mount, and the tab strip above an object's records is the saved-view
-    // switcher (`ViewTabBar`), which renders one tab per `listViews` entry and
-    // reads no `tabs` key. Tombstoned with `retiredKey()` beside the `pageName`
-    // tombstone already on this shape; `ViewTabSchema` stays, reused by the
-    // page-only `userFilters.tabs` preset bar. D2: `view-list-tabs-removed`.
+    // maintainer's #18900 criterion). `ObjectListView.tabs` declared tab
+    // definitions for a multi-tab view interface, and no renderer ever drew them: a
+    // list view's own `tabs` has no reader, and objectui's `TabBar`, the one
+    // component that would draw it, has no production mount. The tab strip above an
+    // object's records is the saved-view switcher (`ViewTabBar`), which renders one
+    // tab per `listViews` entry and reads no `tabs` key. `userFilters.tabs`, a
+    // different key of the same element type, is read and rendered, and stays.
+    // Tombstoned with `retiredKey()` beside the `pageName` tombstone already on
+    // this shape; `ViewTabSchema` stays, reused by the page-only `userFilters.tabs`
+    // preset bar. D2: `view-list-tabs-removed`.
     'ui/ObjectListView:tabs',
     // ADR-0090 D2 (no Profile concept) + ADR-0049 enforce-or-remove; maintainer
     // ruling 2026-09-12, decision batch #121 item 2, verbatim 「同意」.

packages/spec/src/ui/view-list-tabs-retirement.test.ts

@@ -7,10 +7,13 @@
  *
  * `ListViewSchema.tabs` parsed at every list-view door, was stored, and drew
  * nothing. Measured before removal, with lit controls, and recorded on the
- * ledger row (`liveness/view.json`, `/props/list/children/tabs`): objectui's
- * `TabBar` — the one component that reads a `ViewTab[]` — has zero production
- * mounts at the pinned sha, while `ViewTabBar`, the saved-view switcher,
- * mounts in the object view and is fed from `listViews`.
+ * ledger row (`liveness/view.json`, `/props/list/children/tabs`): a list
+ * view's own `tabs` has no reader, and objectui's `TabBar` — the one component
+ * that would draw it — has zero production mounts at the pinned sha, while
+ * `ViewTabBar`, the saved-view switcher, mounts in the object view and is fed
+ * from `listViews`. `userFilters.tabs`, a different key of the same element
+ * type, is read and rendered (the page preset bar) and stays — the BOUNDARY
+ * pinned below.
  *
  * Bookkeeping shapes, pinned below:
  *   1. A `retiredKey()` tombstone on the SHAPE every list-view door is built

packages/spec/src/ui/view.zod.ts

@@ -2773,12 +2773,14 @@ const ListViewShapeSchema = lazySchema(() => strictObject({
    * [#20301] REMOVED — ADR-0049 enforce-or-remove, triage verdict RETIRE by
    * the maintainer's #18900 criterion (mainstream named-view switching is
    * already delivered here, by `listViews`). The key parsed, was stored, and
-   * drew nothing: objectui's `TabBar` — the one component that reads a
-   * `ViewTab[]` — has zero production mounts, and the tab strip above an
-   * object's records is the saved-view switcher (`ViewTabBar`), which renders
-   * one tab per named list view and reads no `tabs` key. Measured with lit
-   * controls and recorded on the ledger row (`liveness/view.json`,
-   * `/props/list/children/tabs`).
+   * drew nothing: a list view's own `tabs` has no reader, and objectui's
+   * `TabBar` — the one component that would draw it — has zero production
+   * mounts. The tab strip above an object's records is the saved-view
+   * switcher (`ViewTabBar`), which renders one tab per named list view and
+   * reads no `tabs` key. (`userFilters.tabs`, a different key of the same
+   * element type, IS read and rendered — the page preset bar — and stays.)
+   * Measured with lit controls and recorded on the ledger row
+   * (`liveness/view.json`, `/props/list/children/tabs`).
    *
    * Tombstoned rather than deleted so the removal is audible in both channels
    * an upgrading author hits — `tsc` (the input type is `never`) and the parse