Introduce a first-class plugin contribution system and SDK, plus frontend integration and installer enhancements.
Backend:
- Add /plugins/manifest-spec and /plugins/contributions endpoints to expose the plugin.json contract and merged active-plugin UI contributions.
- Add app/plugins_sdk for plugin authors (current_user, logger, audit, jwt helpers).
- Add ContributionService to aggregate active plugin contributions (nav, routes, page_titles, command_palette, widgets).
- Marketplace now hands off to plugin installer when an extension has a source URL and enforces admin-only installs in the marketplace API.
- PluginService: run lifecycle hooks (install/uninstall) and install declared template dependencies (best-effort, recorded/logged) during plugin installs; surface template/manifest fields on InstalledPlugin.to_dict; surface linked InstalledPlugin status on ExtensionInstall.to_dict.
Frontend:
- Add runtime contributions loader (plugins/contributions.js) with useContributions hook and resolveComponent/getPluginModule helpers.
- Add SDK re-exports for plugin frontends (plugins/sdk/index.js) and Vite alias 'serverkit-sdk'.
- Integrate contributions across UI: Sidebar, CommandPalette, PluginLoader (declared widgets + legacy fallback), PageTitleUpdater, DashboardLayout (refreshContributions), and route injection via new ExtensionRoutes hook loaded in App.jsx.
- Add API client getPluginContributions and adjust PluginLoader discovery patterns.
Other:
- Add .extension-platform-plan/ to .gitignore.
Overall this enables declarative plugin-driven UI integration (sidebar items, SPA routes, page titles, command palette entries, and widgets), lifecycle hooks, and template dependency installs while keeping legacy behavior for older plugins.
Introduce a plugin installation and management system.
Backend: add InstalledPlugin model, plugin_service with download/install/enable/disable/uninstall, dynamic blueprint registration and frontend manifest generation, and plugins API endpoints (list/get/install/enable/disable/uninstall). Register plugins blueprint and attempt to hot-load installed plugin blueprints at app startup.
Frontend: add PluginLoader component (Vite import.meta.glob) to render plugin widgets, extend Marketplace UI to install/manage plugins, add API client methods for plugins, and update styles for the marketplace plugin UI. This enables installing plugins from GitHub/repos/zips and managing them from the app.
Juan Denis