chore(observability): port Sentry and memory optimizations from klz-2026

sentry.server.config.ts

@@ -0,0 +1,15 @@
+import * as Sentry from '@sentry/nextjs';
+
+const dsn = process.env.SENTRY_DSN;
+const isProd = process.env.NODE_ENV === 'production';
+
+Sentry.init({
+  dsn,
+  enabled: isProd && Boolean(dsn),
+
+  // Adjust this value in production, or use tracesSampler for greater control
+  tracesSampleRate: 1,
+
+  // Setting this option to true will print useful information to the console while you're setting up Sentry.
+  debug: false,
+});