feat(FN-1484): fix agent picker stale cache on project switch

- Clear agent cache when projectId changes in QuickEntryBox and InlineCreateCard
- Add regression tests for agent picker cache invalidation behavior
- Add changeset for @gsxdsm/fusion patch release

packages/dashboard/app/components/QuickEntryBox.tsx

@@ -230,6 +230,12 @@ export function QuickEntryBox({ onCreate, addToast, tasks = [], availableModels,
     }
   }, [description, projectId]);
 
+  // Clear agents cache when projectId changes to prevent stale agents from leaking across projects
+  useEffect(() => {
+    setAgents([]);
+    setSelectedAgentId(null);
+  }, [projectId]);
+
   // Clean up legacy disclosure persistence key from previous versions
   useEffect(() => {
     if (typeof window !== "undefined") {