The TimeoutMiddleware wraps the response writer in *http.timeoutWriter which
doesn't implement http.Flusher. When the admin reverse proxy or WebSocket
upgrader tries to flush, it panics and crashes the container (502 Bad Gateway).
Skip timeout for /admin, /_next, and /ws routes.
Also fix the Dockerfile HEALTHCHECK to detect the worker process — the worker
has no HTTP server so the curl-based check always failed, marking it unhealthy.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
7438dfd9b1