cleanup and fix messages re-rendering while chat is streaming

ui/desktop/src/components/ProgressiveMessageList.tsx

@@ -189,7 +189,7 @@ export default function ProgressiveMessageList({
 
         return (
           <div
-            key={message.id && `${message.id}-${message.content.length}`}
+            key={message.id || `message-${index}`}
             className={`relative ${index === 0 ? 'mt-0' : 'mt-4'} ${isUser ? 'user' : 'assistant'}`}
             data-testid="message-container"
           >

ui/desktop/src/hooks/useSessionStream.ts

@@ -3,10 +3,6 @@ import { Session } from '../api';
 import { useSessionStreamContext } from '../contexts/SessionStreamContext';
 
 interface UseSessionStreamOptions {
-  /**
-   * Whether to enable streaming. If false, will not connect.
-   * @default true
-   */
   enabled?: boolean;
   onUpdate?: (session: Session) => void;
   onError?: (error: string) => void;
@@ -45,7 +41,6 @@ export function useSessionStream(
   const onUpdateRef = useRef(onUpdate);
   const onErrorRef = useRef(onError);
 
-  // Keep refs up to date
   useEffect(() => {
     onUpdateRef.current = onUpdate;
     onErrorRef.current = onError;