run_loop now accepts a single runtime or a list; it steps every camera each tick
(one shared clock read), isolates a per-camera step exception, runs the periodic
sync/heartbeat/flush once, and routes zones per camera via a zones_for(cfg, rt)
callback. parse_cameras() reads CAMERAS='backend:device:camera_id,...' (single-camera
fallback when unset) and refuses to yield zero cameras. zones_from_config() gains a
camera_id filter; PipelineRuntime exposes camera_id. Single-camera behavior unchanged.
Replace the PiCameraSource NotImplementedError stub with a working picamera2 CSI
source (SourcePort read()->(ok,frame), RGB888->BGR to match the pose adapters;
picamera2 lazy-imported as a system package, injected fake in tests). daemon.main()
gains CAMERA_BACKEND (csi|uvc) selecting PiCameraSource or UvcSource.
Replace the NotImplementedError stub with a working HailoPoseAdapter for Pi5 +
Hailo-8. yolov8s_pose has no on-chip NMS, so the adapter does host-side DFL box
decode + keypoint decode + greedy NMS + letterbox un-map + COCO-17 assembly
(numpy decode ported from Hailo's MIT PoseEstPostProcessing, locked by a synthetic
9-tensor unit test; the HailoRT device wiring is gated + device-validated on bringup).
daemon.main() gains a POSE_BACKEND switch (hailo|movenet).
Wrap sync_config, send_heartbeat, and queue.flush operations in separate
try/except to ensure daemon survives periodic operation exceptions. Critical
for unattended 24/7 pilot devices where a locked database or disk error would
otherwise kill the entire loop. Per-frame step() handling unchanged.
