Wire the marketplace to actually install modules from Git repos, verify
manifest signatures, track installations in the store, and auto-load them
as Workers at startup. A module goes from marketplace entry to running
Worker with Install() + LoadModule().
- Add Store.GetAll() for group-scoped key listing
- Create marketplace.Installer with Install/Remove/Update/Installed
- Export manifest.MarshalYAML for test fixtures
- Wire installer into Service with auto-load on startup (step 8)
- Expose Service.Installer() accessor
- Full integration test: install → load → verify store write → unload → remove
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Load() reads .core/view.yml from any directory via io.Medium,
LoadVerified() adds ed25519 signature check. Uses MockMedium for tests.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
