LoRA mel pre-generation runs a full ODE+CFG for every clip, which is slow.
Cache results to a .pt file next to the output, keyed by a SHA-256 hash
of the LoRA adapter content + generation parameters (seed, steps, CFG,
duration, sample rate, npz file list). Automatically reused on subsequent
runs when parameters haven't changed.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>