- Replace ServerConnectivity with CheckServerReachabilityUseCase
- Add InfoApiClient for /api/info endpoint
- Implement ServerInfoRepository with 30s cache TTL and 5s rate limiting
- Update ShareBookmarkViewModel to use ShareExtensionServerCheck manager
- Add server reachability check in AppViewModel on app start
- Update OfflineSyncManager to use new UseCase
- Extend SimpleAPI with checkServerReachability for Share Extension