i18n: default-language picker offers only shipped locales; widen stored bare codes on read

src/workspaces/state/src/useSettings.ts

@@ -5,6 +5,13 @@ import { useAuth } from 'hooks/useAuth';
 
 const QUERY_KEY = ['USER_SETTINGS'];
 
+/**
+ * UI locales went from bare codes to regional BCP 47 tags (docs/localization.md D2). A stale bare
+ * code must resolve rather than fail, and this is a one-time widening on read, not a DB migration.
+ */
+const WIDEN_BARE_LOCALE: Record<string, string> = { en: 'en-GB', pt: 'pt-PT' };
+const widenLocale = (code: string): string => WIDEN_BARE_LOCALE[code] ?? code;
+
 const mergeWithDefaults = (saved: Partial<UserSettings>): UserSettings => ({
   chat: { ...DEFAULT_SETTINGS.chat, ...saved.chat },
   ai: {
@@ -14,7 +21,11 @@ const mergeWithDefaults = (saved: Partial<UserSettings>): UserSettings => ({
   },
   tasks: { ...DEFAULT_SETTINGS.tasks, ...saved.tasks },
   appearance: { ...DEFAULT_SETTINGS.appearance, ...saved.appearance },
-  languages: { ...DEFAULT_SETTINGS.languages, ...saved.languages },
+  languages: {
+    ...DEFAULT_SETTINGS.languages,
+    ...saved.languages,
+    default: widenLocale(saved.languages?.default ?? DEFAULT_SETTINGS.languages.default),
+  },
   tts: { ...DEFAULT_SETTINGS.tts, ...saved.tts },
 });
 
@@ -121,7 +132,7 @@ export const DEFAULT_SETTINGS: UserSettings = {
   },
   languages: {
     spoken: ['en'],
-    default: 'en',
+    default: 'en-GB',
     translateTo: 'en',
   },
   tts: {