test(dogfood): classify page:tabs item visibleWhen in the expression-surface ledger (#2606)

The ADR-0058 D7 / ADR-0060 conformance ratchet re-discovers every
ExpressionInputSchema field in packages/spec/src and fails the build if any is
unclassified. The new tab-item visibleWhen surface (ui/component.zod.ts) needs
a ledger row: it belongs to cel-ui (interpret, fail-soft-log) alongside the
page/view visibility predicates — evaluated by the objectui page:tabs renderer.

Fixes the Test Core / Dogfood Regression Gate failures on this branch.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FmuuXkuW3JH9LYXHHRnoQV

Author: claude

packages/dogfood/test/expression-conformance.ledger.ts

@@ -125,6 +125,11 @@ export const EXPRESSION_SURFACE: ExprSurface[] = [
       'ui/view.zod.ts:visibleWhen',
       'ui/view.zod.ts:visibleOn',
       'ui/component.zod.ts:onSubmit',
+      // Conditional tabs (framework#2606): `page:tabs` item-level visibility.
+      // Canonical ADR-0089 `visibleWhen` from day one (no deprecated alias on
+      // this new surface). Interpreted by the objectui page:tabs renderer to
+      // omit the whole tab (header + panel) when FALSE.
+      'ui/component.zod.ts:visibleWhen',
       'system/settings-manifest.zod.ts:visible',
     ],
   },