Marketplace: third-party distribution and automated plugin submission

[krokoko]

Describe the feature

Support distributing plugins to third-party marketplaces (starting with the Anthropic official marketplace) and automate the submission and update lifecycle.

Currently our plugins are available in the Cursor marketplace. We want to expand distribution to the Anthropic official Claude Code plugin marketplace and potentially other AI assistant marketplaces in the future. This requires:

1. Anthropic marketplace submission - Determine the submission process for the Anthropic official plugin marketplace and submit our existing plugins
2. Automated submission pipeline - Build CI/CD automation to submit new plugins or plugin updates to all target marketplaces when a release is published
3. Version synchronization - Keep plugin versions in sync across all marketplaces so users always get the latest version regardless of where they installed from
4. Multi-marketplace manifest management - Handle any marketplace-specific metadata or manifest differences between Cursor, Anthropic, and future marketplaces

Use Case

As a plugin maintainer, I want plugin releases to automatically propagate to all supported marketplaces so that users discover and install our plugins from their preferred AI assistant, and always have access to the latest version without manual intervention.

Proposed Solution

1. Research phase: Document the submission requirements for the Anthropic official marketplace (API, manual form, manifest format, review process, etc.)
2. Marketplace adapter layer: Create a tools/ script or CI job that translates our canonical plugin.json + marketplace.json into each marketplace's required format
3. CI workflow: Add a GitHub Actions workflow triggered on release tags that:
   • Validates the plugin (existing mise run build)
   • Packages the plugin for each target marketplace
   • Submits/updates the plugin in each marketplace (API calls or CLI commands)
   • Reports status back to the release
4. Version bump automation: Optionally integrate with a release-please or changeset workflow so version bumps in plugin.json automatically trigger the distribution pipeline

Other Information

• Current marketplaces: Cursor
• Target marketplaces: Anthropic official, Cursor (keep existing)
• Related: marketplace.json schema in schemas/marketplace.schema.json

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change