Pi brain host needs ffmpeg for USB webcams, RTSP sources and timelapse assembly

2026-09-07 hotpatch: ffmpeg 7.1.5 installed inside the running dsc-hub-brain container via .audit/cameras-pi-hotpatch.ps1; GET /cameras on the Pi reports ffmpeg true — RTSP capture and timelapse assembly work now. Still open: both brain Dockerfiles carry the apt install for the next image build, and docker-compose maps ${DSC_CAMERA_DEVICE:-/dev/null} → /dev/video0; a webcam on the brain Pi needs DSC_CAMERA_DEVICE=/dev/video0 in .env plus a container recreate on a release image (a recreate drops hotpatched code). Note: the Pi’s /dev/video10–31 are SoC codec nodes, not cameras. USB capture on the Pi remains unverified until a webcam is plugged in.