- ytdlp: thin wrapper around yt-dlp CLI for channel/playlist discovery
(--flat-playlist) and per-video metadata (--print-json); defaults to
player_client=web_embedded to avoid SABR-only format restrictions.
- downloader: YouTube path extracts audio via yt-dlp -x, probes duration
with ffprobe and rejects clips far shorter than the expected length.
- main: YouTube channel/playlist feeds, incremental discovery with
pre-start-date boundary for newest-first channels, two-phase
record-then-enqueue so discovered jobs survive crashes.
- poller: propagate enclosure MIME type; computeDestPath appends the
matching file extension.
- state: jobs carry expected duration; AddJobWithStatus for skipped items.
- cmd/probe: dry-run discovery/date-resolution diagnostics.
