A stalled VOD read blocked the runner forever, so a wedged job held its user and global slot until restart, and on installs without per-user identity (internal port, or auth disabled without a proxy user header) everyone shared one per-user slot. VOD ffmpeg and ffprobe inputs now use a 30 s rw_timeout, a cancel also drops queued parallel runs, a cancelled job stops counting after 60 s, and the per-user limit only applies when the request carries a real username. A failed runner start also stops its requestor.
* refactor motion search
* cleanup dead code and tests
* tweaks
* fix multi-day seeking
* start playback a few seconds before the change so the motion is in view