_pe_dchan_route.nx

_pe_dchan_route.nx -- X-ROOM-DC-002 rung-2 INTEGRATION: client-side private routing + ordering over the nx_signaling_v2 DUMB BROADCAST relay (the relay forwards to everyone; PRIVACY is achieved CLIENT-SIDE by the recipient filter). Two ACTIONS: dr_route(to_id, my_id) -> 1 accept iff the frame is addressed to me, else 0 ignore. dr_seq_ok(prev, new) -> 1 iff per-from seq is strictly monotonic (ordered; rejects replay/regress). Self-validating E2E gate (3 peers A=1,B=2,C=3; A sends a D frame to B): B ACCEPTS, C IGNORES (private achieved on a broadcast relay) + a monotonic per-from seq stream is accepted while a regression is rejected (neg-control = the ordering check actually discriminates, no false-green). FOUNDED on _pe_dchan (frame layer, DONE) + the DC-003 reliability data plane (_pe_dchan_reorder).