fix(tanstackstart-react): Add server-side replayIntegration no-op stub (#21148)

Using `Sentry.replayIntegration()` in shared client/server code (e.g.
`router.tsx`) causes a build error because `@sentry/node` doesn't export
it (noticed this while testing
#21149). Adds a no-op
stub on the server side to get rid of the build error, same pattern as
the existing `tanstackRouterBrowserTracingIntegration` stub.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: nicohrubec

packages/tanstackstart-react/src/index.types.ts

@@ -39,6 +39,7 @@ export declare const unleashIntegration: typeof clientSdk.unleashIntegration;
 
 export declare const wrapMiddlewaresWithSentry: typeof serverSdk.wrapMiddlewaresWithSentry;
 
+export declare const replayIntegration: typeof clientSdk.replayIntegration;
 export declare const tanstackRouterBrowserTracingIntegration: typeof clientSdk.tanstackRouterBrowserTracingIntegration;
 export declare const sentryGlobalRequestMiddleware: typeof serverSdk.sentryGlobalRequestMiddleware;
 export declare const sentryGlobalFunctionMiddleware: typeof serverSdk.sentryGlobalFunctionMiddleware;

packages/tanstackstart-react/src/server/index.ts

@@ -11,6 +11,17 @@ export { wrapMiddlewaresWithSentry } from './middleware';
 export { sentryGlobalRequestMiddleware, sentryGlobalFunctionMiddleware } from './globalMiddleware';
 export { createSentryTunnelRoute } from './tunnelRoute';
 
+/**
+ * A no-op stub of the replay integration for the server. Router setup code is shared between client and server,
+ * so this stub is needed to prevent build errors during SSR bundling.
+ */
+export function replayIntegration(_options?: Record<string, unknown>): Integration {
+  return {
+    name: 'Replay',
+    setup() {},
+  };
+}
+
 /**
  * A no-op stub of the browser tracing integration for the server. Router setup code is shared between client and server,
  * so this stub is needed to prevent build errors during SSR bundling.