feat(client): adopt the locale seat in theme, sidebar, question, and model

Each package ships its zh/en dictionaries as satisfies-typed pairs (zh is
the key-set source of truth; en is checked complete against it), merges its
namespace into LocaleNamespaceMap, and declares locale: NS at register —
components read the framework-injected typed t seat instead of a
hand-carried inject member. Overlapping verbatim words (retry, submit,
submitting) drop out of package dictionaries in favor of the shared common
vocabulary; the question composer stores validation feedback as dictionary
keys so shown feedback follows a locale switch.

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

@@ -11,6 +11,7 @@ import {
 } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { PropsLocale, PropsRuntime, PropsStore } from '@deepseek-ai/dsh-client-ui-slots'
 import type { ThemePreference } from './index.ts'
+import type { ThemeKey } from './locales.ts'
 import type {} from './settings-contract.ts'
 import type { createAppearanceRowStore } from './settings-store.ts'
 import css from './AppearanceRow.module.css'
@@ -27,7 +28,7 @@ export type AppearanceRowComponentProps =
   & PropsLocale<'settings.theme'> & AppearanceRowInjected
 
 /** Cube order and icons (figma 501:30015-30017: Light, Dark, System). */
-const CUBES: readonly { id: ThemePreference; labelKey: 'appearance.light' | 'appearance.dark' | 'appearance.system'; Icon: typeof IconLightOutline16 }[] = [
+const CUBES: readonly { id: ThemePreference; labelKey: ThemeKey; 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

@@ -14,9 +14,11 @@ import type {} from '@deepseek-ai/dsh-client-locale/client'
 import type { AppearanceRowInjected } from './AppearanceRow.tsx'
 import { AppearanceRow } from './AppearanceRow.tsx'
 import { createAppearanceRowStore } from './settings-store.ts'
+import { en, zh, type ThemeKey } from './locales.ts'
 
 export type { AppearanceRowComponentProps, AppearanceRowInjected } from './AppearanceRow.tsx'
 export type { AppearanceRowState } from './settings-store.ts'
+export type { ThemeKey } from './locales.ts'
 
 /** Namespace owning this feature's settings-row copy. */
 export const SETTINGS_NS = 'settings.theme'
@@ -24,7 +26,7 @@ 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'
+    'settings.theme': ThemeKey
   }
 }
 
@@ -235,20 +237,7 @@ export function apply(ctx: ClientContext): void {
   const theme = new ThemeService(ctx)
   ctx.provide('theme', theme)
 
-  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')
+  ctx.effect(() => ctx.locale.register(SETTINGS_NS, { zh, en }), 'ui-theme: settings row dictionaries')
 
   const store = createAppearanceRowStore()
   let bound: BoundActions<typeof store> | undefined

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

@@ -0,0 +1,20 @@
+/** `settings.theme` namespace dictionaries (the Appearance row's copy). */
+
+/** Simplified Chinese dictionary (the key-set source of truth). */
+export const zh = {
+  'appearance.title': '外观',
+  'appearance.light': '浅色',
+  'appearance.dark': '深色',
+  'appearance.system': '跟随系统',
+} satisfies Record<string, string>
+
+/** The settings.theme namespace key union. */
+export type ThemeKey = keyof typeof zh
+
+/** English dictionary, checked complete against the zh key set. */
+export const en = {
+  'appearance.title': 'Appearance',
+  'appearance.light': 'Light',
+  'appearance.dark': 'Dark',
+  'appearance.system': 'System',
+} satisfies Record<ThemeKey, string>