Phase 1: Code Editor Integration
- Add Monaco Editor to vendor directory
- Create editor.html component with full Monaco integration
- Create API endpoints for file operations (editor.rs)
- GET /api/editor/file/:file_path - Read file
- POST /api/editor/file/:file_path - Save file
- GET /api/editor/files - List files
- Features:
- File tree sidebar
- Multi-file tabs
- Syntax highlighting for 10+ languages
- Auto-save with WebSocket sync preparation
- Keyboard shortcuts (Ctrl+S, Ctrl+P)
- Status bar with language, encoding, cursor position
- Custom GB dark theme
- Publish integration with deployment modal
