Add dedicated architecture support for ACE-Step music generation model LoRAs
with optimizations informed by the v1.5 hybrid attention architecture — cross-
attention is the primary voice-identity pathway (always global, attending to
timbre+lyric+text conditioning), while self-attention alternates sliding window
(local timbre) and global GQA (long-range structure).
Changes:
- New `acestep_dit` preset: wider orthogonal band (0.30), higher TIES threshold
(0.35), full magnitude preservation (floor 1.0) — biases toward SLERP over
TIES to prevent voice signal trimming in cross-attn layers
- Fix `to_out` → `o_proj` normalization bug (was producing `out_proj`)
- Add v1.0 detection and normalization (transformer_blocks, speaker_embedder,
lyric_encoder mapped to v1.5 canonical form)
- Refine WAN detection to exclude transformer_blocks (prevents v1.0 misdetect)
- Add `acestep_dit` to all architecture_preset UI dropdowns
- 25 new tests (detection, normalization, preset)
- Technical reference doc with architecture analysis and design rationale
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
