Refactor Next.js configuration and remove Sentry integration

- Updated `serverExternalPackages` in the Next.js configuration to exclude `@sentry/node`, improving compatibility with React's RSC/client boundary.
- Removed the `instrumentation.ts` file and refactored Sentry-related code to a no-op, ensuring it does not interfere with the Next.js build process.
- Simplified the dashboard page by integrating `DashboardGuildGrid`, enhancing the user interface and reducing complexity in the component structure.

apps/webui/src/lib/sentry.ts

@@ -1,43 +1,20 @@
-let initialized = false;
-
+/**
+ * WebUI error reporting stub.
+ *
+ * `@sentry/node` is intentionally not used in the Next.js app: importing it
+ * (even lazily via `instrumentation.ts`) pulled OpenTelemetry into the build
+ * graph and broke page-data collection with
+ * `TypeError: createContext is not a function`. Bot-side Sentry remains in
+ * `apps/bot`. Capture here stays a structured console fallback so call sites
+ * can keep using one API.
+ */
 export async function initWebuiSentry(): Promise<void> {
-  if (initialized) {
-    return;
-  }
-  const dsn = process.env.SENTRY_DSN?.trim();
-  if (!dsn) {
-    return;
-  }
-
-  // Import only when a DSN is configured. Loading `@sentry/node` at module
-  // scope patches Node builtins and can break Next.js page-data collection
-  // (`createContext is not a function`) during `next build`.
-  const Sentry = await import('@sentry/node');
-  Sentry.init({
-    dsn,
-    environment: process.env.NODE_ENV ?? 'production',
-    release: 'nexumi-webui@0.1.0',
-    tracesSampleRate: process.env.NODE_ENV === 'production' ? 0.1 : 1.0,
-    initialScope: {
-      tags: { service: 'webui' }
-    }
-  });
-  initialized = true;
+  // no-op in WebUI
 }
 
 export async function captureWebuiException(
   error: unknown,
   context?: Record<string, unknown>
 ): Promise<void> {
-  const dsn = process.env.SENTRY_DSN?.trim();
-  if (!dsn) {
-    return;
-  }
-  const Sentry = await import('@sentry/node');
-  Sentry.withScope((scope) => {
-    if (context) {
-      scope.setExtras(context);
-    }
-    Sentry.captureException(error);
-  });
+  console.error('[webui]', error, context ?? {});
 }