feat(vscode-ide-companion): refactor message components with modular architecture

Refactor UI message rendering by extracting message types into dedicated components. Add ChatHeader component for better session management interface.

- Extract message components: UserMessage, AssistantMessage, ThinkingMessage, StreamingMessage, WaitingMessage
- Add ChatHeader component with session selector and action buttons
- Delete MessageContent.css and consolidate styles into App.scss
- Update Tailwind config for component styling
- Improve message rendering with proper TypeScript typing

packages/vscode-ide-companion/src/agents/qwenConnectionHandler.ts

@@ -101,6 +101,14 @@ export class QwenConnectionHandler {
             lastSession.sessionId,
           );
           sessionRestored = true;
+
+          // Save auth state after successful session restore
+          if (authStateManager) {
+            console.log(
+              '[QwenAgentManager] Saving auth state after successful session restore',
+            );
+            await authStateManager.saveAuthState(workingDir, authMethod);
+          }
         } catch (switchError) {
           console.log(
             '[QwenAgentManager] session/switch not supported or failed:',