src/node/main.c: ctrl_enum_cb was discarding menu_count and menu_items,
causing empty dropdowns for all MENU/INTEGER_MENU controls. Added a
menu item pool (MAX_MENU_POOL=128 items) to Ctrl_Build; the callback now
copies items into the pool and sets menu_count/menu_items on the control.
docs/protocol.md: add missing sections — str8 primitive, ENUM_DEVICES,
ENUM_CONTROLS (with control type/flag tables and menu item notes),
GET_CONTROL, and SET_CONTROL schemas.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Both sites default to site_id=0; gateway must rewrite site_id in
announcements and protocol messages crossing the boundary. site_id=0
on a cross-site link is a gateway protocol error.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Covers all layers: TCP → transport frame → message type dispatcher →
payload schemas. Documents frame format (6-byte header), all message
types, STREAM_OPEN/CLOSE lifecycle, codec/pixel_format/origin tables,
stream events, and discovery announcement wire format.
Also fixes stale channel_id reference in audio section of architecture.md.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
