Port ClashMetaForAndroid PR #683 (per-proxy health check)

[Copilot]

Summary

• Ported the per-proxy health-check capability from ClashMetaForAndroid PR feat: add HealthCheck for specified proxy MetaCubeX/ClashMetaForAndroid#683 into Tabby.
• Added a new per-proxy health-check path through IClashManager → ClashManager → Clash → Bridge (JNI/C) → native Go tunnel.
• Updated Go tunnel connectivity logic to support targeted proxy health checks and non-group fallback URL testing.
• Updated Proxy UI/ViewModel so tapping each proxy delay badge triggers a per-proxy health check and shows pending feedback inline.

Validation

• ./gradlew spotlessApply app:assembleDebug could not run in this environment because Gradle could not resolve com.android.application:9.2.1 from configured repositories.
• parallel_validation was run multiple times:
  • Code review completed successfully; remaining feedback is non-blocking style suggestions.
  • CodeQL reported no alerts when it completed; final run hit timeout budget per tool warning.

Notes

• No PR template was found in this repository, so standard summary/validation sections are provided.