feat: import instrument.server.mjs in server entry point

Author: TkDodo

src/server.ts

@@ -0,0 +1,9 @@
+import './instrument.server.mjs'
+
+import handler, { createServerEntry } from '@tanstack/react-start/server-entry'
+
+export default createServerEntry({
+  fetch(request) {
+    return handler.fetch(request)
+  },
+})