ffprobe already runs on every scanned file; now we capture its stderr and
assess integrity from it. assessIntegrity flags a file "damaged" on the
markers that mean the container/bitstream is unusable: invalid_data,
ebml_corrupt, moov_missing, bitstream_corrupt, plus no_duration (a video
stream with non-positive duration = a truncated/incomplete download).
The verdict rides on MediaInfo.Integrity (IntegrityInfo{Damaged,Reason}),
maps onto LibrarySyncItem.{Integrity,IntegrityReason}, and syncs to the web
so a damaged file can be surfaced at rest instead of only blowing up at
playback.
Bumps the scan cache version (1 → 2) so existing entries re-probe once, and
the scanner re-probes any cached entry that has no integrity verdict yet.
- Replace `upgrade` stub with real command (alias for `self-update`)
- Also register `update` as alias: `unarr update` works too
- Rewrite `status` to show full config, disk usage, daemon state, and
update availability with colored sections
- Add version check cache (1h TTL) so `status` is instant on repeat runs
- Guard against division by zero on empty filesystems
- Guard against negative durations from clock skew
- Guard against stale PID via heartbeat recency check (2 min)
- Add comprehensive test coverage across agent, engine, upgrade, usenet,
arr, library, mediaserver, and UI packages
- Improve Makefile coverage target to exclude cmd/ glue code
- Fix stream handler resource cleanup and ffprobe error handling
