feat(localization): add i18next configuration and CLI commands for localization management

frontend/package.json

@@ -9,7 +9,10 @@
     "build:check": "tsc -b && node ./scripts/build.js",
     "lint": "eslint .",
     "preview": "vite preview",
-    "test": "vitest run src/components/admin/__tests__/ThemeCustomizerEnhanced.test.tsx"
+    "test": "vitest run src/components/admin/__tests__/ThemeCustomizerEnhanced.test.tsx",
+    "i18n:extract": "i18next-cli extract",
+    "i18n:status": "i18next-cli status",
+    "i18n:ci": "i18next-cli extract --ci --dry-run"
   },
   "dependencies": {
     "@tanstack/react-query": "^5.0.0",
@@ -66,6 +69,7 @@
     "eslint-plugin-react-hooks": "^5.2.0",
     "eslint-plugin-react-refresh": "^0.4.20",
     "globals": "^16.2.0",
+    "i18next-cli": "^1.56.11",
     "jsdom": "^25.0.1",
     "postcss": "^8.5.10",
     "tailwindcss": "^3.3.0",