Git panel: share checkout actions + fix push loading (#20)

* Update files

* Git panel: share checkout actions

Hoist checkout-scoped async git actions into a shared store and keep primary Push CTA loading in-place. Also stabilize e2e git flows.

* Stabilize git panel async actions and fix e2e flakes

packages/app/src/query/query-client.ts

@@ -0,0 +1,14 @@
+import { QueryClient } from "@tanstack/react-query";
+
+export const queryClient = new QueryClient({
+  defaultOptions: {
+    queries: {
+      staleTime: Infinity,
+      gcTime: Infinity,
+      refetchOnMount: false,
+      refetchOnReconnect: false,
+      refetchOnWindowFocus: false,
+    },
+  },
+});
+