- bg_color options: green/blue/black/white (default: green) - Previews saved as JPG, SelectActorPreview outputs [N,H,W,3] RGB - Removed merge_segments_rgba() and all RGBA/WebM logic - 3-channel BGR throughout — no alpha overhead
- bg_color options: green/blue/black/white (default: green) - Previews saved as JPG, SelectActorPreview outputs [N,H,W,3] RGB - Removed merge_segments_rgba() and all RGBA/WebM logic - 3-channel BGR throughout — no alpha overhead