🔨 chore: add trpc mock.vite stub to stop Vite SPA warmup from traversing server router (#13022)

Made-with: Cursor

src/libs/trpc/mock.vite.ts

@@ -0,0 +1,7 @@
+/**
+ * Browser-only stub to stop Vite SPA warmup from traversing the server router graph.
+ * The real implementation is only valid in server and test environments.
+ */
+export const createCaller = () => {
+  throw new Error('`@/libs/trpc/mock` is server-only and unavailable in the Vite browser build.');
+};