Release labels

You can now attach key/value labels to a service release — the same labeling model already on services and environments. Tag a release with whatever your CI already knows — the owning team, a hotfix flag, the upstream pipeline run — and read it back from ryvn describe release or the release detail page to drive your own rollback, promotion, and audit logic. Pass repeatable --label key=value flags to ryvn create release from the CLI, declare them under labels: in your <service>-release.ryvn.yaml metadata file, or edit them inline from the release page in the app.