AbstractMusic v0.1.3

Added

• Added a MkDocs documentation build and GitHub Pages deployment path to the release workflow.
• Added release rehearsal support for manually dispatched releases, including explicit publish
  confirmation before PyPI publication.
• Added AI-readable documentation indexes with llms.txt and llms-full.txt.
• Added troubleshooting and release-process documentation for installation, local runtime,
  Apple/MPS, Stable Audio, and publishing workflows.
• Added Dependabot configuration for GitHub Actions and Python dependency maintenance.

Changed

• Documented the AbstractMusic text-planning boundary, including deterministic fallback planning
  and host-injected planning services.
• Documented the default ACE-Step Diffusers backend as the package-owned acestep route, with
  Hugging Face model weights allowed and external ACE-Step source/runtime code excluded.
• Documented Apple MPS dtype behavior for ACE-Step Diffusers, preferring stable MPS dtypes before
  CPU fallback.

Fixed

• Made Python 3.10 test metadata compatible by using tomli where tomllib is unavailable.
• Hardened release validation to refuse duplicate PyPI versions before publishing.