The real sky-cam repo's capture.sh already replaces MotionEye/any NVR
itself (plain ffmpeg RTSP frame-grab) - it and daily_sunrise_video.sh's
optional audio capture are the only places that touch a camera's RTSP
URL directly. Every other script (4-seasons, montage-mvt, year-end-join,
moon-track, moon-phase-monthly) only reads JPEGs/audio already on disk.
So the entire motionEye->Frigate transition is pointing CAM_RTSP_<cam>
at Frigate's go2rtc restream (rtsp://<frigate-host>:8554/<cam>) instead
of the camera directly - no upstream script changes needed. Replaces
the previous frigate-retime.sh/export-API approach, which solved a
problem (matching an arbitrary recording length to music duration) that
sky-cam's own 4-seasons.sh/montage-mvt.sh already handle via JPEG frame
counts.