The release workflow moves from .gitea to .github: macOS on the
macos-signing runner, Windows and Linux (WSL) on ely-windows. The
persistent clones fetch from GitHub. ci.sh creates or reuses the tag's
release through GitHub's API and replaces a rerun's assets of the same
name; the update manifests point at GitHub's download URLs.
Co-Authored-By: Claude <noreply@anthropic.com>