nx_mp_relay_gate.nx

nx_mp_relay_gate.nx -- proves the sovereign daemon roster serializer (nx_mp_relay) over nx_room_relay. NO JS, NO curl: a pure-nx gate. The daemon serializes OTHER live players into [len][frame] records that the wasm parses with gi_net_ingest_roster. This is the /roster GET body, proven sovereignly. 1) serialize 2 peers in a room -> 2 records, frame bytes byte-EXACT, in slot order 2) room isolation (neg): a peer in another room is not in the body 3) self excluded (neg): the requesting player never sees itself 4) staleness (neg): a peer past TTL is dropped from the body Built nx_cc_sovereign -> nxasm_x86 (no gcc, no .sh). license_tier: ORIGINAL