ServerContext.send_dmrd(pkt) hands one DMRD frame to the routing core,
through the same synthetic ingress path scheduled announcements use
(inject_plugin_dmrd -> dmrd_received on the announcement MASTER, with
the SERVER_ID as peer). Only plugins listed in PLUGINS.send get it.
Guards (PluginDmrdSender, re-read from the live config on every frame):
- allowed_src_ids: a plugin can't send as a radio; required.
- max_frames_per_s: per-plugin token bucket, starts full.
- unit data only in this version (data header, rate 1/2, 3/4, CSBK).
- master_kill or removing the entry stops sending at once.
Routing of plugin frames (dmrd_received plugin_origin):
- delivered by the unit data path only: SUB_MAP / hotspot peer ID, to
the destination's exact hotspot, also on the ingress MASTER itself;
- never through the private call path, which would learn the plugin's
source in SUB_MAP (spreading replies over every hotspot of that
MASTER) and keep call state on its shared slot;
- no OpenBridge or DATA-GATEWAY fan-out;
- plugin events for them carry is_synthetic=True.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>