fix(diagnosis): prevent progress stream blocking and refine tunnel type chips (#230)

* 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.

vite-frontend/src/pages/forward/diagnosis.ts

@@ -1,5 +1,6 @@
 export interface ForwardDiagnosisEntry {
-  success: boolean;
+  success?: boolean;
+  diagnosing?: boolean;
   description: string;
   nodeName: string;
   nodeId: string;