The router treated any server-stamped principal as a bound lane, so with the
flag ON every authenticated dashboard/API session lost the legacy browser
backend even when no extension controller ever registered (scope_for_session
returns None -> ControllerUnavailable, no fallback) — while check_fns still
advertised the tools via the legacy OR-gate.
New broker.lane_registered() distinguishes the two cases:
- lane never registered -> generic callers keep the legacy backend
- lane registered (controller offline/ambiguous) -> fail closed, unchanged —
a control-this-tab session never silently jumps to another browser
Also makes the four non-allowlisted wrapped tools (cdp/console/vision/
get_images) behave correctly for never-registered lanes (legacy backend)
while staying fail-closed for registered lanes.
Surfaced during review of PR #85351.
Generic Hermes callers still use the existing browser backend when extension control is disabled or no server-bound controller identity exists.
Once the gateway binds a controller identity, missing scope, disconnect, or capability loss now fail closed instead of silently switching a control-this-tab request to another local or cloud browser. Covers the schema-build to dispatch disconnect race.
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.
kshitijk4poor