release-workspace

Run the multi-crate workspace release process for metrics-rs/metrics: audit unreleased changes, plan version bumps and changelog entries, then execute per-crate (cargo-release publish + per-PR comments + S-awaiting-release label removal) with explicit gates between crates. Invoke with /release-workspace when the user asks to prepare/run a release, says "what's ready to release?", or wants to drain the…