refactor: enterprise architecture restructure and streamlined cursor rules

- Consolidated cursor rules into 4 concise files (always, react, electron, database)
- Removed legacy .cursorrules file and redundant rule files
- Team members feature: extracted dialogs, modals, and utilities
- File browser: split FileCard into composable components
- Workflows: extracted context, dialogs, and hooks
- Database: modularized schema into core.sql + feature modules
- Added Zustand-first state management patterns
- Updated types and permissions for new architecture

Author: eldinmiller