Fix stale approval dialog reappearing after page refresh

The message persist effect only triggered on message count changes,
so approval state updates (which modify tool state within existing
messages) were never saved to localStorage. On refresh, stale
approval-requested state was restored. Now saves messages immediately
after approval submission.

frontend/src/hooks/useAgentChat.ts

@@ -629,6 +629,11 @@ export function useAgentChat({ sessionId, isActive, onReady, onError, onSessionD
       if (hasApproved) {
         updateSession(sessionId, { isProcessing: true });
       }
+
+      // Persist updated tool states so a page refresh during execution
+      // won't restore stale approval-requested state from localStorage.
+      saveMessages(sessionId, chatActionsRef.current.messages);
+
       return true;
     },
     [sessionId, chat, updateSession, setNeedsAttention],