Wires the T17 protocol's optional modifier profile through the server's room-create flow:
- rooms.Room gains an optional profile field; RoomRegistry.createRoom/joinRoom accept and echo it.
- GameSession constructor + GameSessionRegistry.create pass the profile through to ChessEngine's EngineOptions so modifier facts get seeded and the integration preset auto-activates at game start.
- broadcast.handleRoomCreate validates an inline profile via chess's validateProfile against the resolved layout, mapping validator codes (E_PROFILE_*) onto the wire protocol's MODIFIER_PROFILE_* family. Invalid profiles produce a non-fatal error and leave room / session state untouched; the creator is not bound.
- room.created and room.joined echo the active profile when present, so late joiners render piece modifier badges on first paint.
- RoomCreatedPayloadSchema and RoomJoinedPayloadSchema gain matching optional profile fields.
- @paratype/chess barrel: re-exports CaptureFlag + validateProfile + ModifierValidation* types so the server can consume them without reaching into internals.
Tests: 5 new cases (happy path, join echo, backward compat, INVULN_KING rejection, layout-invalid precedence). Full check green (1213/1213).
Joey Yakimowich-Payne
4c8e8467b7