Fix race condition: ignore streaming events from old sessions

- Added sessionIdRef to track current session
- When clearing session, generate new session ID
- Event listeners check if sessionId matches before updating state
- Prevents old streaming responses from appearing in new sessions
- All quality checks passing

src/components/Chat.tsx

@@ -22,6 +22,7 @@ export function Chat({ projectPath, onCloseProject }: ChatProps) {
   const [streamingContent, setStreamingContent] = useState("");
   const messagesEndRef = useRef<HTMLDivElement>(null);
   const inputRef = useRef<HTMLInputElement>(null);
+  const sessionIdRef = useRef(Date.now());
 
   // Token estimation and context window tracking
   const estimateTokens = (text: string): number => {
@@ -102,13 +103,21 @@ export function Chat({ projectPath, onCloseProject }: ChatProps) {
   }, [model]);
 
   useEffect(() => {
+    const currentSessionId = sessionIdRef.current;
+
     const unlistenUpdatePromise = listen<Message[]>("chat:update", (event) => {
-      setMessages(event.payload);
-      setStreamingContent(""); // Clear streaming content when final update arrives
+      // Only update if this is still the current session
+      if (sessionIdRef.current === currentSessionId) {
+        setMessages(event.payload);
+        setStreamingContent(""); // Clear streaming content when final update arrives
+      }
     });
 
     const unlistenTokenPromise = listen<string>("chat:token", (event) => {
-      setStreamingContent((prev) => prev + event.payload);
+      // Only append tokens if this is still the current session
+      if (sessionIdRef.current === currentSessionId) {
+        setStreamingContent((prev) => prev + event.payload);
+      }
     });
 
     return () => {
@@ -174,6 +183,8 @@ export function Chat({ projectPath, onCloseProject }: ChatProps) {
     );
 
     if (confirmed) {
+      // Generate new session ID to ignore old streaming events
+      sessionIdRef.current = Date.now();
       setMessages([]);
       setStreamingContent("");
       setLoading(false);