chore(i18n): drop unshipped locales (de, zh)

AVAILABLE_LOCALES advertised 'de' and 'zh' but src/i18n/locales/
only ships en.ts, es.ts, fr.ts. Selecting de or zh from the new
hub language picker would 404 the dynamic import.

- src/i18n/index.ts: AVAILABLE_LOCALES = ['en', 'es', 'fr']
- src/composables/useLocale.ts: trim flag map to match

VITE_DEFAULT_LOCALE still drives first-run default.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/composables/useLocale.ts

@@ -27,9 +27,7 @@ export function useLocale() {
     const flagMap: Record<string, string> = {
       'en': '🇬🇧',
       'es': '🇪🇸',
-      'fr': '🇫🇷',
+      'fr': '🇫🇷'
-      'de': '🇩🇪',
-      'zh': '🇨🇳'
     }
     return flagMap[locale] || '🌐'
   }

src/i18n/index.ts

@@ -5,7 +5,7 @@ import { useStorage } from '@vueuse/core'
 import en from './locales/en'
 
 // Define available locales
-export const AVAILABLE_LOCALES = ['en', 'es', 'fr', 'de', 'zh'] as const
+export const AVAILABLE_LOCALES = ['en', 'es', 'fr'] as const
 export type AvailableLocale = typeof AVAILABLE_LOCALES[number]
 
 // Type for our messages