feat(localization): add i18next extraction helper & refactor backup configuration component to tsx

frontend/package.json

@@ -60,6 +60,7 @@
     "@testing-library/jest-dom": "^6.6.3",
     "@testing-library/react": "^16.1.0",
     "@testing-library/user-event": "^14.6.1",
+    "@types/node": "^25.6.2",
     "@types/react": "^18.3.12",
     "@types/react-dom": "^18.3.1",
     "@vitejs/plugin-react": "^4.5.3",
@@ -71,6 +72,7 @@
     "globals": "^16.2.0",
     "i18next-cli": "^1.56.11",
     "jsdom": "^25.0.1",
+    "memfs": "^4.57.2",
     "postcss": "^8.5.10",
     "tailwindcss": "^3.3.0",
     "typescript": "~5.8.3",