The outcome video render applied one fighter list (both match fighters) to the
whole clip, so the referee LoRA and winner-only identity only existed in the
keyframe, not at video-generation time. Thread per-segment fighters through
_render: segments are now (prompt, frames, seg_stem, seg_fighters) and each
segment (and each chained part) applies exactly its own character_profiles +
LoRAs, overriding the clip-level list.

Outcome segments now load: FINISH = both fighters; VICTORY = winner + referee
(decisive) or both fighters + referee (draw). Referee resolution matches the
keyframe path. Backward compatible — shorter segment tuples and legacy clips
without role/fighters fall back to the clip-level fighters.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>