Seat 1 (P2) can bring its LOCAL slot-1 card to a match: it uploads the card
to the host at launch over the new recomp-net MEMCARD op, the host installs
it as the match's slot-2 card, and the usual card broadcast carries it to
everyone. The host's real slot-2 file is rebound to netplay/guest_card2.mcd
for the session and restored on shutdown; guests already sandbox both slots.
Lobby side: a per-seat memcard_offer on set_ready (has_card, share), a host
allow flag in match_caps, and guest_memcard_active settled ONCE by the host
at start and shipped with the launch, so a toggle racing the start cannot
split the room. LAN carries the same over MOTK5 UPDATE / MEMCARD / JOIN
tail / a trailing START line. PSX_NET_GUEST_MEMCARD=1 for CLI sessions;
a host waiting on a card that never comes stalls at a named phase
(mc_guest_wait), not a silent "ok".
Two latent guest-sandbox bugs fixed on the way: a disabled slot 2 had no
bound path, so a host blob carrying a card for it failed to import and the
guest stalled forever; and leaving the sandbox re-bound a disabled slot to
the sandbox file. Both slots are now bound in the sandbox and restored per
slot (memcard_rebind_path, which can also unbind).
Lobby chat: the client keeps a ring fed by the server's echo (op:chat);
LAN rooms relay through the host (MOTK5 CHATREQ guest->host, MOTK5 CHAT
host->everyone). Wired to the launcher's chat_send/chat_count/chat_get.
Also carries the spectator-seat work that was in the tree alongside this
(spectator seats in the lobby client, spectator_wire_slot in the launch).
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V1dT6h1ZshMVUUVKTPxsCD
Wire lib/retcomm-rbengine beside recomp-net and replace MotK in-tree sched,
hash_confirm, input hist, snap ring, and rb_post with thin PSX shims so the
ecosystem can share invent/pacing policy outside each title facade.
Co-authored-by: Cursor <cursoragent@cursor.com>