fix(hub): the NAT-punch signal needs a shared active group, like the offer relay

2026-09-26T00:44:52Z

POST /v1/nodes/{id}/incoming checked only the caller's own address, then revealed whether the node was connected (404 vs 504) and, with QUIC on, made it punch — so any authenticated account could poll it for a node's liveness or make a stranger's node emit a UDP probe. The membership gate webrtc_offer did inline is now require_shared_active_group() in api/signaling.py, called by both routes; in notify_incoming it runs before anything depends on the node's connection state, so a non-member gets one uniform 403 whether the node is up or not. test_incoming_membership.py holds it (a non-member is refused with a membership 403 whether the node is connected or not; a member passes the gate); red before, green after. The offer relay is unchanged in behaviour (it now calls the shared helper); signaling/availability suites pass. Design §7.2 updated. Co-Authored-By: Claude Opus 4.8

meshbay.git/packages/meshbay-hub/tests/test_incoming_membership.py, branch main

fix(hub): the NAT-punch signal needs a shared active group, like the offer relay