* refactor: update AppHandle usage to use Arc<AppHandle> for improved memory management
* fix: clippy ci
* fix: ensure default_latency_test is safely accessed with non-null assertion
- Fixed getSystemProxyActualState logic to properly check actual system status
- Unified system proxy state display across all components
- Replaced systemProxyIndicator with actualState for consistent UI display
- Updated components: setting-system, ProxyControlSwitches, proxy-tun-card
- Added entry to v2.4.0 changelog