- Implement `--prepare` flag in draft2final CLI to update front matter without
  PDF generation, including automatic migration of `format/theme` to `as/style`.
- Refactor boilerplate injection: decentralize configuration templates from the
  CLI into transmuter packages via a new `getBoilerplate()` contract method.
- Update `@vmprint/contracts` to include `getBoilerplate` in the Transmuter interface.
- Add CLI flag aliases: `--using` (as), `--theme` (style), and `--out` (output)
  for improved UX and backward compatibility.
- Documentation cleanup:
    - Migrate User Guide links to draft2final.app.
    - Remove obsolete `/docs/draft2final` directory.
    - Add "Preparing Existing Files" section to draft2final documentation.
- Update starter templates for manuscript and screenplay formats with latest keys.
- Bump draft2final version to v1.0.1.