menubar: drop unused @tanstack/react-query

Scaffold leftover with zero consumers — the renderer's only resident is
the Pair window (bare useEffect + one IPC call), and the planned plan
usage / token stats rows are native NSMenu items built in the MAIN
process (fetch/cache/refresh all Node-side), where a renderer query
cache can't help.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: yyq1025

packages/menubar/package.json

@@ -24,7 +24,6 @@
   },
   "dependencies": {
     "@sidecodeapp/daemon": "workspace:*",
-    "@tanstack/react-query": "^5.94.0",
     "electron-updater": "^6.8.9",
     "react": "^19.2.6",
     "react-dom": "^19.2.6",

packages/menubar/src/main.tsx

@@ -1,4 +1,3 @@
-import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { StrictMode } from "react";
 import { createRoot } from "react-dom/client";
 import App from "./App";
@@ -15,15 +14,11 @@ const applyTheme = () =>
 applyTheme();
 themeQuery.addEventListener("change", applyTheme);
 
-const queryClient = new QueryClient();
-
 const root = document.getElementById("root");
 if (!root) throw new Error("no #root");
 
 createRoot(root).render(
   <StrictMode>
-    <QueryClientProvider client={queryClient}>
-      <App />
-    </QueryClientProvider>
+    <App />
   </StrictMode>,
 );