fix: use promptRef.current in setPromptFromTraits to keep stable callback identity

Read from promptRef.current instead of closing over the prompt state
variable so the useCallback dependency array no longer includes prompt.
This restores the previous ref-based pattern that kept the callback
identity stable across keystrokes, preventing unnecessary re-renders of
the provider traits menu.

Author: cursoragent

apps/web/src/components/chat/ChatComposer.tsx

@@ -868,7 +868,8 @@ export const ChatComposer = memo(
     // ------------------------------------------------------------------
     const setPromptFromTraits = useCallback(
       (nextPrompt: string) => {
-        if (nextPrompt === prompt) {
+        const currentPrompt = promptRef.current;
+        if (nextPrompt === currentPrompt) {
           scheduleComposerFocus();
           return;
         }
@@ -879,7 +880,7 @@ export const ChatComposer = memo(
         setComposerTrigger(detectComposerTrigger(nextPrompt, nextPrompt.length));
         scheduleComposerFocus();
       },
-      [composerDraftTarget, prompt, promptRef, scheduleComposerFocus, setComposerDraftPrompt],
+      [composerDraftTarget, promptRef, scheduleComposerFocus, setComposerDraftPrompt],
     );
 
     const providerTraitsMenuContent = renderProviderTraitsMenuContent({