feat: ddd identify - recover 'Artist - Title' for unnamed/mislabeled tracks via acoustic fingerprint (fpcalc/Chromaprint + AcoustID, free). GUI tab with per-track confirm (nothing renamed until you click), CLI --validate mode to calibrate confidence threshold against your own library. Requires a free AcoustID API key (acoustid.org/new-application) via Settings or 'ddd config set acoustid_api_key'. Note: even high-confidence matches can be wrong (samples/edits share fingerprints) - always review before applying.