Agent Skills: promote

Runs the full release workflow for the current project. Commits any uncommitted changes, pushes to remote, creates and merges a PR if on a feature branch, determines the next semver version from conventional commits, creates an annotated git tag and GitHub release with generated notes, cleans up merged branches, and returns to a clean main. Use when the user says promote, ship, release, commit and push, tag and release, or get back to main.