b0382e77ae
Add a public Plugin Marketplace page covering both audiences: operators using the in-app catalog (Browse/Installed tabs, one-click install, Update to vX, the Sources dialog for team/corporate registries, plugin icons, feature-flag gating, sideloading still works) and plugin authors publishing into it (one-repo-per-plugin GitHub Release assets, the optional manifest icon field, submitting a plugins.yaml PR to the official catalog, GitHub-stars-only ranking, and hosting your own index.json source). Also cross-link the new page from plugins.md (replacing the now-false "No plugin marketplace" security note), plugins-authoring.md, and plugins-manifest.md (new icon field row); register it in meta.json and coverage.json. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>