Two bugs fixed:
1. SDI capture sidecar never had /dev/blackmagic bound — ffmpeg opened the
decklink input inside a container with no device nodes, so frame=0.
Fix: local spawns now push '/dev/blackmagic:/dev/blackmagic' onto Binds
when source_type='sdi'.
2. recorders.js always spawned sidecars against the local Docker socket
(zampp1), even when a recorder's node_id pointed at zampp2 (where the
card is). Fix: resolveNodeTarget() looks up the recorder's cluster node;
if it's a different hostname the sidecar is spawned via a new
POST /sidecar/start endpoint on the remote node-agent.
node-agent gains three new routes (all talk to the local Docker socket):
POST /sidecar/start — create + start container (host network,
privileged, /dev/blackmagic bind for sdi)
DELETE /sidecar/:id — stop + remove
GET /sidecar/:id/status — inspect + poll capture service
docker-compose.worker.yml: add /var/run/docker.sock and LIVE_DIR to
node-agent so it can spawn sidecars, and document build-capture prerequisite.: docker-compose.worker.yml
The agent now uses network_mode: host so os.hostname() and the network
interface list reflect the actual host instead of a per-container random
hex hostname (root cause of duplicate Zampp2 rows) and a 172.x docker
bridge IP. Also passes NODE_IP and BMD_MODEL through for explicit overrides.
