- Added Manifest struct to encapsulate plugin metadata and installation details.
- Implemented ManifestFromRelease and ManifestFromPlugin functions for creating manifests from releases and plugins.
- Enhanced Plugin struct to include Versions and InstallPlan for direct installations.
- Introduced validation for direct install type, ensuring artifacts are correctly specified.
- Updated registry validation to support new schema version and direct install requirements.
- Added tests for parsing and validating direct install plugins, ensuring correct artifact handling.
Replace the tag-pinned release lookup with the repository latest
release endpoint. Derive the plugin version from the release tag,
validate it, and attach an optional token to API requests to raise
the rate limit.
