test(gui): settings package suites; ledger-judged re-registration

Full per-file coverage for the three settings packages: invariant
companions, store mirroring with revision guards, behavior-shaped
section/shell specs (props-fed, real store engine), and apply-level
suites on a real Context + SlotCore covering declaration-aware deferral
and HMR collapse recovery. All three registrants now judge presence on
the slot ledger instead of a local disposer, which went stale when a
parent redeclaration cascade removed the entry (ds-review-bot finding);
the locale re-register path keeps the same idempotence.

packages/client/ui-settings/tests/apply.spec.ts

@@ -0,0 +1,120 @@
+/** Settings shell registration: declaration-aware deferral, the injected face, and HMR recovery. */
+import { Context } from 'cordis'
+import { describe, expect, it, vi } from 'vitest'
+import { SlotsService } from '@deepseek-ai/dsh-client-runtime/client'
+import { LocaleService } from '@deepseek-ai/dsh-client-locale/client'
+import { apply, inject } from '@deepseek-ai/dsh-client-ui-settings/client'
+import type { SettingsRootInjected } from '@deepseek-ai/dsh-client-ui-settings/client'
+import { SettingsRoot } from '../src/client/SettingsRoot.tsx'
+
+async function bench() {
+  const ctx = new Context()
+  await ctx.plugin(SlotsService).await()
+  const locale = new LocaleService(ctx)
+  ctx.provide('locale', locale)
+  return { ctx, slots: ctx.get('slots') as SlotsService, locale }
+}
+
+function declare(slots: SlotsService): () => void {
+  return slots.register(
+    { name: 'root', children: { 'sidebar.settings': { kind: 'single', scope: 'root' } } } as never,
+    () => null,
+  )
+}
+
+function injectedOf(slots: SlotsService): SettingsRootInjected {
+  const entry = slots.entries('sidebar.settings')[0]!
+  return (entry.inject as () => SettingsRootInjected)()
+}
+
+describe('ui-settings apply', () => {
+  it('declares the services it uses', () => {
+    expect(inject).toEqual(['slots', 'locale'])
+  })
+
+  it('registers the shell for declarations that arrive before or after apply', async () => {
+    const before = await bench()
+    declare(before.slots)
+    await before.ctx.plugin({ inject: [...inject], apply }).await()
+    expect(before.slots.entries('sidebar.settings')[0]!.component).toBe(SettingsRoot)
+    expect(before.slots.spec('settings.section')).toEqual({ kind: 'list', scope: 'root' })
+
+    const after = await bench()
+    await after.ctx.plugin({ inject: [...inject], apply }).await()
+    expect(after.slots.entries('sidebar.settings')).toHaveLength(0)
+    declare(after.slots)
+    await Promise.resolve()
+    expect(after.slots.entries('sidebar.settings')[0]!.component).toBe(SettingsRoot)
+    // The self-inflicted ledger notifications hit the duplicate guard.
+    expect(after.slots.entries('sidebar.settings')).toHaveLength(1)
+  })
+
+  it('registers the zh/en shell dictionaries and disposes them with the fiber', async () => {
+    const b = await bench()
+    declare(b.slots)
+    const fiber = b.ctx.plugin({ inject: [...inject], apply })
+    await fiber.await()
+    expect(b.locale.bind('settings')('title')).toBe('设置')
+    b.locale.setLocale('en')
+    expect(b.locale.bind('settings')('close')).toBe('Close')
+    await fiber.dispose()
+    // The (ns, locale) seats are free again — the dictionary disposers ran.
+    expect(() => b.locale.register('settings', 'zh', {})).not.toThrow()
+    expect(() => b.locale.register('settings', 'en', {})).not.toThrow()
+  })
+
+  it('exposes translate over "<ns>:<key>" refs with literal echo for plain text', async () => {
+    const b = await bench()
+    declare(b.slots)
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    const injected = injectedOf(b.slots)
+    expect(injected.translate('settings:title')).toBe('设置')
+    expect(injected.translate('no colon ref')).toBe('no colon ref')
+  })
+
+  it('projects the section ledger into ordered nav rows with option defaults', async () => {
+    const b = await bench()
+    declare(b.slots)
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    const injected = injectedOf(b.slots)
+    expect(injected.sections()).toEqual([])
+    b.slots.register({ name: 'settings.section', id: 'z', order: 20, label: 'Z' } as never, () => null)
+    b.slots.register({ name: 'settings.section', id: 'a' } as never, () => null)
+    expect(injected.sections()).toEqual([
+      { id: 'a', order: 0, label: '' },
+      { id: 'z', order: 20, label: 'Z' },
+    ])
+    expect(injected.sectionsVersion()).toBe(b.slots.getVersion('settings.section'))
+    const listener = vi.fn()
+    const off = injected.subscribeSections(listener)
+    b.slots.register({ name: 'settings.section', id: 'b', order: 1, label: 'B' } as never, () => null)
+    await Promise.resolve()
+    expect(listener).toHaveBeenCalled()
+    off()
+  })
+
+  it('re-registers after an HMR collapse re-declares the slot (stale disposer must not block)', async () => {
+    const b = await bench()
+    const redeclare = declare(b.slots)
+    await b.ctx.plugin({ inject: [...inject], apply }).await()
+    expect(b.slots.entries('sidebar.settings')).toHaveLength(1)
+    // Declarer unload: the cascade removes our entry and the slot spec while
+    // our local disposer variable goes stale.
+    redeclare()
+    expect(b.slots.entries('sidebar.settings')).toHaveLength(0)
+    declare(b.slots)
+    await Promise.resolve()
+    expect(b.slots.entries('sidebar.settings')[0]!.component).toBe(SettingsRoot)
+    expect(b.slots.spec('settings.section')).toEqual({ kind: 'list', scope: 'root' })
+  })
+
+  it('unregisters the shell and collapses settings.section on teardown', async () => {
+    const b = await bench()
+    declare(b.slots)
+    const fiber = b.ctx.plugin({ inject: [...inject], apply })
+    await fiber.await()
+    await fiber.dispose()
+    expect(b.slots.entries('sidebar.settings')).toHaveLength(0)
+    expect(b.slots.spec('settings.section')).toBeUndefined()
+  })
+})