The lossy converter fix handler now reads delete_original from its
own job settings (repair.jobs.lossy_converter.settings.delete_original)
instead of the global lossy_copy.delete_original. Defaults to false.
Separate from the per-download Blasphemy Mode toggle in Settings.
New library maintenance job that scans for FLAC files missing a lossy
copy (MP3/Opus/AAC) and creates findings. Fix action converts via
ffmpeg using the configured codec/bitrate from Settings. Supports
Blasphemy Mode (delete original + update DB path). Finding details
store codec/bitrate from scan time for consistency. Disabled by
default, manual-run only, no auto-schedule.