fix: remove duplicate deep link handler in App.tsx

A deep link handler already existed at line 275 (with proper project
switching and test coverage). The duplicate added earlier caused double
toast rendering in tests.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/dashboard/app/App.tsx

@@ -197,27 +197,6 @@ function AppInner() {
       .catch(() => {/* keep empty array on failure */});
   }, []);
 
-  // Handle deep link to task on mount (from ntfy Click URLs)
-  useEffect(() => {
-    const params = new URLSearchParams(window.location.search);
-    const taskId = params.get("task");
-    if (!taskId) return;
-
-    // Clean URL immediately without reloading
-    const url = new URL(window.location.href);
-    url.searchParams.delete("task");
-    url.searchParams.delete("project");
-    window.history.replaceState({}, "", url.toString());
-
-    fetchTaskDetail(taskId)
-      .then((task) => {
-        handleDetailOpen(task);
-      })
-      .catch(() => {
-        addToast(`Task ${taskId} not found`, "error");
-      });
-  }, []); // eslint-disable-line react-hooks/exhaustive-deps
-
   // Favorite provider/model toggle handlers (shared by ListView bulk edit)
   const handleToggleFavorite = useCallback(async (provider: string) => {
     const currentFavorites = favoriteProviders;