- Remove all Nightwatch E2E test files and configuration
- Remove chromedriver and nightwatch dependencies from package.json
- Update E2E commands to use Playwright directly without :playwright suffix
- Simplify E2E command structure for better developer experience
- Add @super-productivity/plugin-api package with TypeScript definitions
- Define core plugin interfaces, types, and manifest structure
- Add plugin hooks system for event-driven architecture
- Create plugin API type definitions and constants
- Add documentation and development guidelines