[AlexGeslani]

Outcome

Completes the local-first authoritative multiplayer loop through live opponent state, immutable result resolution, and mutual rematch.

Safety and authority

• server-authoritative match IDs, seeds, results, and rematch transitions
• room-lifetime match-ID uniqueness and exact client fencing
• strict WebSocket path/origin/Host validation and bounded payloads
• bounded graceful shutdown with forced lingering-connection teardown
• Rematch acceptance is intentionally irrevocable until the fresh authoritative match starts

Verification

• npm test: 245/245 passing across 72 suites
• real two-browser dev acceptance: PASS
• malformed Host raw upgrade: HTTP 400; server remains responsive
• incomplete HTTP-request SIGTERM reproduction: PASS
• independent fail-closed review: PASS, no security concerns or logic errors
• browser evidence SHA-256: 20a8ecaec83593ddd49506bde14a16bc7e6a02c4cd4f0ac31315a33962ba5165