Race condition: scanner re-scanned folders while post-processing was
still moving files, causing partial matches and ghost failures. Now
tracks in-progress paths and skips them on subsequent scans.
Coverage penalty fix: individual tracks that match at 80%+ confidence
now auto-import even when overall album coverage is low (e.g. 2 of 18
tracks present). Previously low coverage killed the entire import.
Import page: stats bar, filter pills, Scan Now, Approve All, Clear
History (clears imported + failed), live scan progress.