- Add 25s heartbeat ping from backend to prevent Apache/proxy idle-timeout
killing the connection during 1-3 min analysis runs
- Handle heartbeat silently in both analyzeProof and analyzeWIPProof frontend handlers
- Run PDF rasterization via asyncio.to_thread so heartbeats aren't blocked
- Wrap analyze_proof with asyncio.wait_for(timeout=300) for a hard 5-min cap
- Log dropped send_message calls in ConnectionManager instead of swallowing silently
- cloudrun.yaml: add sessionAffinity, startup probe, raise containerConcurrency 4→10,
document DISABLE_AUTH option
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
