Thumbnails failed immediately on any clip past ~2 min. The one-pass select
expression joined frames with a flat a+b+c+... chain, which overflows ffmpeg's
recursive expression parser past ~120 terms ("Error while parsing expression").
Join the same terms as a balanced tree (depth O(log N)) instead — identical
selection, still one decode pass, exact per-tile frames preserved.
- generate_thumbnails management command: runs synchronously and streams each
phase to stdout, so jobs are watchable without tailing app logs
- surface ffmpeg's stderr instead of swallowing it in CalledProcessError
- fly: min_machines_running = 1. Background thumbnail jobs outlive the HTTP
request that triggers them, so scale-to-zero let the proxy autostop the VM
mid-job and leave projects stuck "running"
- timeline: replace the two split playhead bars (pinned lanes vs scrolling
tracks) with one full-height overlay, positioned in JS to track horizontal
scroll and sit above the translucent header
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
