- README: add 'What's different from OpenGD77' (incl. the new SK2 mute) and a
dedicated 'Flashing' section (DFU steps, per-model flash.sh, donor note).
- scripts/forgejo-release.sh: build/attach a single platform or all, reuse an
existing release, replace same-named assets, and warn if freetrxVersion.h
doesn't match the tag.
- TOOLS.md: document the platform build argument.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
