* fix(diagnosis): avoid result channel deadlock in progress stream
Close the diagnosis result channel asynchronously after workers complete so progress can stream without blocking, and improve tunnel card type chip contrast for clearer protocol distinction.
* feat(diagnosis): stream pending items and render in-progress states
Pre-populate diagnosis stream with pending targets so tunnel and forward dialogs can show per-item diagnosing status immediately. Update result typing and UI states to distinguish in-progress, success, and failure rows/cards consistently.
- Add SSE streaming endpoints for tunnel/forward diagnosis with real-time progress
- Increase diagnosis timeout to 2 minutes with context propagation
- Group forwards by tunnel within user groups in UI
- Add nginx SSE proxy configuration for streaming endpoints
sagit