40fddc9e4c
The gateway half of the going-idle/buffered-flip primitive (scale-to-zero PRIMITIVE, not the behaviour). Integrates with the EXISTING drain transition: - ws_transport: `go_idle()` sends `going_idle` + awaits the connector's `going_idle_ack` (connector-authoritative flip-then-ack, Q-5.3c — stays serving until the ack so nothing is lost in the flip window); acks a buffered inbound (bufferId present) via `inbound_ack` after the handler runs (drain-without-dup on the delivery leg); NET-NEW reconnect loop re-dials + re-handshakes after an unexpected close (off by default, on in production). - adapter: emits `going_idle` from its existing `disconnect()` drain seam before tearing down the socket; best-effort + guarded (never blocks shutdown). - transport Protocol + contract doc §3.2 document the 3 new frames. +6 relay tests (124 pass). NOT in scope: the autonomous idle timer / machine suspend / NAS health model (deferred behaviour). Ben's relay-adapter solo lane.