Treat unexpected controller transport loss as recoverable until each command's original deadline. Same-identity reconnects refresh transport and capability state, flush deferred cancels before new dispatch, and can complete already-started work.
Keep explicit detach and different controller/browser identity replacement terminal, owner-gate every inbound lifecycle frame, distinguish slow in-flight WebSocket writes from real send failures, and exclude browser-control session identity from shared shell snapshots.
Keep extension control opt-in and preserve existing browser backends unless an exact server-bound controller is available. Centralize protocol and capability admission across API and dashboard transports, make selected-controller results authoritative, bypass stale availability caches only inside bound requests, and serialize structured results for the existing tool contract.
Add a real browser_snapshot route-table/WebSocket E2E, strict admission and ownership regressions, public configuration and protocol documentation, and tests proving feature-off/no-controller compatibility.