- Extend core/plugin-sdk types with runtime manifest metadata, runtime factory, and runtime registration exports
- Add runtime validation in plugin manifest parsing, including runtimeId slug and semver checks
- Add PluginLoader.getPluginRuntimes() and PluginRunner runtime cache/invalidation plumbing across plugin lifecycle events
- Expand plugin loader/runner test coverage for runtime discovery and cache behavior, and document runtime registration in PLUGIN_AUTHORING.md
- Add PluginSlot component for rendering plugin UI placeholders at designated dashboard locations
- Add usePluginUiSlots hook with 60-second TTL cache for slot definitions
- Add fetchPluginUiSlots API wrapper and PluginUiSlotEntry type
- Add UI slots documentation section to plugin authoring guide
- Add PluginSlot integration tests for TaskCard, Column, Header, SettingsModal, and TaskDetailModal
- Update CI Status example plugin to demonstrate uiSlots registration
- Fix JSX namespace import in PluginSlot.tsx for TypeScript compatibility
