only typegen.watch during dev (#12299)

Author: pcattori

packages/react-router-dev/vite/plugin.ts

@@ -747,10 +747,12 @@ export const reactRouterVitePlugin: ReactRouterVitePlugin = () => {
         rootDirectory =
           viteUserConfig.root ?? process.env.REACT_ROUTER_ROOT ?? process.cwd();
 
-        Typegen.watch(rootDirectory, {
-          // ignore `info` logs from typegen since they are redundant when Vite plugin logs are active
-          logger: vite.createLogger("warn", { prefix: "[react-router]" }),
-        });
+        if (viteCommand === "serve") {
+          Typegen.watch(rootDirectory, {
+            // ignore `info` logs from typegen since they are redundant when Vite plugin logs are active
+            logger: vite.createLogger("warn", { prefix: "[react-router]" }),
+          });
+        }
 
         reactRouterConfigLoader = await createConfigLoader({
           rootDirectory,