Cut a release of this repository (the CloudZero plugin marketplace itself — not a customer-facing plugin). Promotes every touched plugin's own `Unreleased` changelog section to a dated entry, synthesizes those changes into a new SemVer section at the top of the root `CHANGELOG.md`, bumps `.claude-plugin/marketplace.json`'s version, runs the full CI validation suite locally, tags the release, publishes a GitHub Release, and opens the companion docs PR against `Cloudzero/cloudzero-documentation`'s `v2.0` branch so customer-facing docs land in step with the code. This is a maintainer-only, repo-local skill (lives in `.claude/skills/`, not inside a `plugins/*/skills/` directory) — it is never installed by marketplace consumers. Use when told "cut a release", "release the marketplace", "ship a new version", "promote the changelog", or after merging PR(s) that need a version bump and a docs update — mirroring how v1.2.0 (the Model Right Sizer launch) shipped.