fix(cli): remove side-effect from agent:end state updater (#133)

Use a ref to track current stream text so agent:end can commit the
final message without calling setMessages inside a setCurrentStreamText
updater function, which violates React's rule that state updaters must
be pure.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/cli/src/tui/app.tsx

@@ -52,6 +52,7 @@ export function TuiApp({
   const [availableModels, setAvailableModels] = useState<ModelInfo[]>([]);
 
   const socketRef = useRef<Socket | null>(null);
+  const currentStreamTextRef = useRef('');
 
   // Fetch available models on mount
   useEffect(() => {
@@ -102,20 +103,22 @@ export function TuiApp({
 
     socket.on('agent:start', () => {
       setIsStreaming(true);
+      currentStreamTextRef.current = '';
       setCurrentStreamText('');
     });
 
     socket.on('agent:text', (data: { text: string }) => {
-      setCurrentStreamText((prev) => prev + data.text);
+      currentStreamTextRef.current += data.text;
+      setCurrentStreamText(currentStreamTextRef.current);
     });
 
     socket.on('agent:end', () => {
-      setCurrentStreamText((prev) => {
-        if (prev) {
-          setMessages((msgs) => [...msgs, { role: 'assistant', content: prev }]);
-        }
-        return '';
-      });
+      const finalText = currentStreamTextRef.current;
+      currentStreamTextRef.current = '';
+      setCurrentStreamText('');
+      if (finalText) {
+        setMessages((msgs) => [...msgs, { role: 'assistant', content: finalText }]);
+      }
       setIsStreaming(false);
     });