The statistics parsed from the JoinRoom reply were reachable only from the
library. They answer the question `room users` already exists to ask -- who
is in here, and are they worth downloading from -- so they belong on its
output rather than behind a second call.
- proto: room.member_stats, with a RoomUserStatsDto carrying status, share
counts, free slots and country
- SessionApi::room_member_stats, so local and remote sessions stay
interchangeable; the status word is decoded through one shared helper
rather than a third copy of the match
- `room users` now emits status, average_speed, shared_files,
shared_folders, slots_free and country, each null when the server said
nothing, documented in SKILL.md
- docs/openrpc.json regenerated from the wire types