- Server gracefully handles EADDRINUSE (logs notice, continues without server) - POST /claim endpoint with referral-based async handoff: 202 (pending) -> poll with referral_id -> 200/401/408 - GET /claim shows current owner and pending queue - DOS protection: 503 when MAX_PENDING_CLAIMS (10) reached - Claims expire after 5 minutes - Pi commands: /webhook:status, /webhook:claim, /webhook:release