- Import ReactNode type from react instead of JSX
- Update PluginSlot return type to ReactNode for proper null type inclusion
- This fixes type safety since the function returns null in error cases
- 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
- Add fetchPluginUiSlots API wrapper with PluginUiSlotEntry type
- Add usePluginUiSlots hook with 30-second TTL cache for slot data
- Add PluginSlot component with error boundary and placeholder rendering
- Add comprehensive tests for hook (cache behavior, error handling, isolation)
- Add comprehensive tests for component (render states, error boundary)
