Custom transition triggers in Studio can now have a visual_effect assigned
(fade_to_black, crossfade, blur_out_in). When triggered during scene splitting,
the effect fires at that scene boundary: the sampler decodes the latent window
around the boundary, applies the pixel-space effect, and re-encodes in-place.
No new nodes needed — VAE is already connected to the scene chain sampler.
New transition_duration input controls how many pixel frames are affected.
New scene_boundaries output provides the boundary list for debugging.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
