feat(client): typed locale standard seat in the slot framework

Registrations declare a dictionary namespace (locale: NS) and the renderer
synthesizes a typed t prop for the entry's component from the installed
LocaleFace; the seat binding is re-derived per locale revision, so a language
switch hands out fresh t references and memoized consumers re-render through
ordinary shallow comparison. LocaleNamespaceMap is the declare-merge table
(namespace -> dictionary key union); TranslateNS<'ns'> is the
namespace-addressed translate type (namespace keys plus the shared common
vocabulary), carried by the t seat and by the locale service's typed bind.

LocaleService implements the face (lookup ns -> common -> zh -> key,
revision-carrying snapshots with subscriber isolation) and installs it
through the boot-once slots.installLocale seam, mirroring the renderer
install. The typed register(ns, {zh, en}) overload checks each dictionary
against the namespace's key union and requires every shipped locale, so a
missing or extra key and an unbalanced translation are compile errors.
Dictionary registration bumps the face revision without emitting
locale/change — the event now means exactly 'the active locale switched',
so registration-heavy boot cannot storm event listeners.

packages/client/ui-theme/src/client/AppearanceRow.tsx

@@ -9,26 +9,25 @@ import clsx from 'clsx'
 import {
   IconDarkOutline16, IconFollowsystemOutline16, IconLightOutline16,
 } from '@deepseek-ai/dsh-client-ui-primitives'
-import type { PropsRuntime, PropsStore } from '@deepseek-ai/dsh-client-ui-slots'
+import type { PropsLocale, PropsRuntime, PropsStore } from '@deepseek-ai/dsh-client-ui-slots'
 import type { ThemePreference } from './index.ts'
 import type {} from './settings-contract.ts'
 import type { createAppearanceRowStore } from './settings-store.ts'
 import css from './AppearanceRow.module.css'
 
-/** Injected business face: namespace-bound translate + the preference write. */
+/** Injected business face: the preference write (t rides the standard locale seat). */
 export interface AppearanceRowInjected {
-  /** Translate a `settings.theme` dictionary key to the active-locale text. */
-  t: (key: string) => string
   /** Switch the theme preference. */
   setTheme: (id: ThemePreference) => void
 }
 
-/** Full component props: runtime share + store share + injected face. */
+/** Full component props: runtime share + store share + locale seat + injected face. */
 export type AppearanceRowComponentProps =
-  PropsRuntime<'settings.general.item'> & PropsStore<ReturnType<typeof createAppearanceRowStore>> & AppearanceRowInjected
+  PropsRuntime<'settings.general.item'> & PropsStore<ReturnType<typeof createAppearanceRowStore>>
+  & PropsLocale<'settings.theme'> & AppearanceRowInjected
 
 /** Cube order and icons (figma 501:30015-30017: Light, Dark, System). */
-const CUBES: readonly { id: ThemePreference; labelKey: string; Icon: typeof IconLightOutline16 }[] = [
+const CUBES: readonly { id: ThemePreference; labelKey: 'appearance.light' | 'appearance.dark' | 'appearance.system'; Icon: typeof IconLightOutline16 }[] = [
   { id: 'light', labelKey: 'appearance.light', Icon: IconLightOutline16 },
   { id: 'dark', labelKey: 'appearance.dark', Icon: IconDarkOutline16 },
   { id: 'system', labelKey: 'appearance.system', Icon: IconFollowsystemOutline16 },

packages/client/ui-theme/src/client/index.ts

@@ -21,6 +21,13 @@ export type { AppearanceRowState } from './settings-store.ts'
 /** Namespace owning this feature's settings-row copy. */
 export const SETTINGS_NS = 'settings.theme'
 
+declare module '@deepseek-ai/dsh-client-ui-slots' {
+  interface LocaleNamespaceMap {
+    /** The Appearance settings row's copy. */
+    'settings.theme': 'appearance.title' | 'appearance.light' | 'appearance.dark' | 'appearance.system'
+  }
+}
+
 /** Theme token dictionary: --dsw-alias-* overrides keyed by variable name. */
 export type ThemeTokens = Record<string, string>
 
@@ -228,23 +235,20 @@ export function apply(ctx: ClientContext): void {
   const theme = new ThemeService(ctx)
   ctx.provide('theme', theme)
 
-  ctx.effect(() => {
-    const disposers = [
-      ctx.locale.register(SETTINGS_NS, 'zh', {
-        'appearance.title': '外观',
-        'appearance.light': '浅色',
-        'appearance.dark': '深色',
-        'appearance.system': '跟随系统',
-      }),
-      ctx.locale.register(SETTINGS_NS, 'en', {
-        'appearance.title': 'Appearance',
-        'appearance.light': 'Light',
-        'appearance.dark': 'Dark',
-        'appearance.system': 'System',
-      }),
-    ]
-    return () => { for (const dispose of disposers) dispose() }
-  }, 'ui-theme: settings row dictionaries')
+  ctx.effect(() => ctx.locale.register(SETTINGS_NS, {
+    zh: {
+      'appearance.title': '外观',
+      'appearance.light': '浅色',
+      'appearance.dark': '深色',
+      'appearance.system': '跟随系统',
+    },
+    en: {
+      'appearance.title': 'Appearance',
+      'appearance.light': 'Light',
+      'appearance.dark': 'Dark',
+      'appearance.system': 'System',
+    },
+  }), 'ui-theme: settings row dictionaries')
 
   const store = createAppearanceRowStore()
   let bound: BoundActions<typeof store> | undefined
@@ -258,7 +262,6 @@ export function apply(ctx: ClientContext): void {
     // first render (the store's revision guard drops stale duplicates).
     sync(theme.getTheme())
     return {
-      t: ctx.locale.bind(SETTINGS_NS),
       setTheme: (id) => { theme.setTheme(id) },
     }
   }
@@ -269,6 +272,7 @@ export function apply(ctx: ClientContext): void {
         id: 'appearance',
         order: 10,
         store,
+        locale: SETTINGS_NS,
         inject: injected,
       }, AppearanceRow))
     return () => { deferred.dispose() }

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

@@ -73,7 +73,8 @@ describe('ui-theme apply', () => {
     const { instance, face } = faceOf(b.slots)
     // The inject-time re-sync sealed the init window: the mirror is current.
     expect(instance.getSnapshot().preference).toBe('dark')
-    expect(face.t('appearance.dark')).toBe('深色')
+    // Copy rides the standard locale seat: the entry declares the namespace.
+    expect(b.slots.entries(SLOT).find(e => e.component === AppearanceRow)!.locale).toBe(SETTINGS_NS)
 
     face.setTheme('system')
     expect(theme.getTheme().preference).toBe('system')