- selva_feature_extractor: cache hash now includes resolved duration;
same video + different duration override no longer returns stale features
- selva_sampler: MPS-safe noise generation (torch.Generator on CPU then
move to device, same pattern as PrismAudioSampler)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Calls update_seq_lengths with actual feature dimensions (not seq_cfg) to
avoid rounding assertion mismatches. Progress bar tracks each Euler step.
Supports negative prompts for steering, normalizes output to [-1,1].
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>