nx_pets_mp_relay_gate.nx

nx_pets_mp_relay_gate.nx -- proves multiplayer pixelmon player-state transport: the sovereign player-state codec (nx_pets_netstate) carried over the sovereign server-relay (nx_room_relay) = no WebRTC/STUN/TURN/WebSocket. Each player POSTs a packed snapshot; another player reads the roster, fetches that peer's frame, unpacks it -> its decoded position/species. This is the exact transport MP-R1/R2 build on. 1) round-trip: A & B in a room -> A sees B in roster + decodes B's pos/species (B's z is NEGATIVE -> exercises sign-extended i32 decode) 2) room isolation (neg-control): a peer in another room never appears 3) staleness: peers past TTL drop from the roster 4) bad-magic reject (neg-control): ps_unpack on garbage returns 0, no fabricated data 5) anti-tautology: A's decoded state != B's decoded state (real per-peer frames) Built nx_cc_sovereign -> nxasm_x86 (no gcc, no .sh). license_tier: ORIGINAL