Every app/api route handler now goes through withRouteLogging, which logs a correlated reqId/method/path/status/duration for each request and turns any uncaught error into a logged stack trace plus a clean JSON 500 instead of Next's default opaque failure. proxy.ts logs rejected auth attempts, and instrumentation.ts's onRequestError catches anything that still escapes a route handler. Also adds a minimal not-found page matching the app's card styling. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>