v1.8

New feature: Burn Subtitles (File → Burn Subtitles...)
Hardcode an .ass subtitle track into a video by re-encoding through libass.
- Live mpv preview of the styled subtitles (same renderer as the burn, so
  preview matches output) — supports ASS effects (\move, \fad, transforms)
- Output fps control (default 30) for smooth effects on low-fps sources
- Robust path handling, libx264/mpeg4 fallback, audio stream-copied,
  progress + cancel

Bug fix: radio-video seeking jumped 50s
At 5fps with the default 250-frame GOP, keyframes were 50s apart, so players
jumped 50s per seek. Now -g 5 -keyint_min 5 → 1-second keyframes (seekable).