Migrate from electron-store to OS-level secure storage (getSecureStorage)

- Replace `electron-store` with OS-level encrypted storage for secure token, userId, and language management in `LocalSystem` and `keyManager`.
- Add `init-user` IPC handler to initialize user data and manage encryption keys.
- Update login process to handle encrypted storage saving with fallback for macOS issues.
- Add offline warning component to `login/page.tsx` to handle first-time sync requirements.
- Remove `electron-store` and associated dependencies from `package.json` and `package-lock.json`.

package.json

@@ -16,7 +16,6 @@
   "license": "ISC",
   "description": "",
   "devDependencies": {
-    "@types/electron-store": "^1.3.1",
     "@types/js-cookie": "^3.0.6",
     "@types/jsonwebtoken": "^9.0.10",
     "@types/node": "^24.10.1",
@@ -52,7 +51,6 @@
     "antd": "^5.28.1",
     "autoprefixer": "^10.4.22",
     "axios": "^1.13.2",
-    "electron-store": "^11.0.2",
     "i18next": "^25.6.2",
     "js-cookie": "^3.0.5",
     "next": "^16.0.3",