v0.6.1

Bug fixes

• Fix crash on embedded image track extraction — when ffmpeg failed to extract a VOBSUB or PGS subtitle track (e.g. corrupted stream, unsupported mux format), the CalledProcessError propagated and aborted extraction for all remaining tracks on that video. The fix catches the error per-track and skips the failing one, so other tracks continue normally. Text tracks (SRT, ASS) are unaffected.