fix(i18n): address PR review feedback

Bugs:
- GeneralPage: network access toast used the keep-server-running title key
  (wrong semantic scope). Add networkAccess.updatedTitle and use it.
- GeneralPage: fallback "Unknown" version was stored as a translated string
  in state, so it stayed stale across language switches. Store null, resolve
  the label at render time.
- GeneralPage: memoize the zod resolver on t and retrigger validation when
  the locale changes so existing error messages retranslate.
- GpuPage: adding t to the CUDA progress EventSource effect deps caused the
  SSE connection to be torn down and reopened on every language change,
  potentially dropping in-flight download events. Capture t in a ref.
- HistoryTable: Effects dialog still rendered English "Source" / "Select
  source version" / "Cancel" / "Apply" / "Applying..." — localize them.
- Locales: zh-CN / zh-TW / ja devSuffix was missing the leading space before
  "(开发版)"/"(開發版)"/"(開発版)", so dev builds rendered "v0.4.2(开发版)"
  instead of "v0.4.2 (开发版)".

Nits:
- ModelManagement: rename .find((t) => ...) callback param to avoid
  shadowing useTranslation().t.
- GenerationPage: rename chunkLimit.value interpolation key from count →
  chars so i18next doesn't silently activate pluralization if a translator
  later adds _one/_other forms.
- LanguageSelect: narrow onValueChange handler param to LanguageCode.

Key count now 559 across en/zh-CN/zh-TW/ja (added 4 effectsDialog keys
plus networkAccess.updatedTitle).

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

app/src/components/ServerTab/LanguageSelect.tsx

@@ -6,7 +6,7 @@ import {
   SelectTrigger,
   SelectValue,
 } from '@/components/ui/select';
-import { SUPPORTED_LANGUAGES } from '@/i18n';
+import { type LanguageCode, SUPPORTED_LANGUAGES } from '@/i18n';
 
 export function LanguageSelect() {
   const { i18n } = useTranslation();
@@ -16,7 +16,7 @@ export function LanguageSelect() {
     <Select
       value={current}
       onValueChange={(value) => {
-        void i18n.changeLanguage(value);
+        void i18n.changeLanguage(value as LanguageCode);
       }}
     >
       <SelectTrigger className="h-9 w-[180px]">