docs: add implementation plan and update documentation

- Add comprehensive implementation plan for universal sync system
- Update README with API reference and device setup guides
- Add KOBO_SETUP.md device configuration guide

README.md

@@ -374,22 +374,43 @@ Complete API testing collection in `bruno/` directory:
 
 ```
 bruno/
-├── user/           # Authentication & profile endpoints
+├── user/              # Authentication & profile endpoints
 ├── admin/          # Admin-only operations  
 ├── library/        # Library management
-├── media-items/    # Media content browsing
+├── media-items/     # Media content browsing
 ├── ebooks/         # Ebook-specific operations
 ├── notes/          # Notes API testing
 ├── highlights/     # Highlights API testing
 ├── scanner/        # Background scanning & watch mode
 ├── progress/       # Reading progress tracking
-└── collection.bru  # Main dashboard
+├── devices/        # Device management
+├── conflicts/       # Sync conflict resolution
+├── queue/          # Sync queue management
+├── sync-koreader/ # KOReader sync protocol
+├── sync-kobo/       # Kobo sync protocol
+└── collection.bru   # Main dashboard file
 ```
 
 ### Authentication Flow
 1. **Register**: `POST /api/auth/register` → JWT token
-2. **Login**: `POST /api/auth/login` → JWT token  
+2. **Login**: `POST /api/auth/login` → JWT token
 3. **Protected Routes**: Use `Authorization: Bearer {token}` header
+4. **Refresh Token**: `POST /api/auth/refresh` → JWT token
+5. **Logout**: `POST /api/auth/logout` → Revoke refresh token
+
+### API Reference Documentation
+See [API_REFERENCE.md](API_REFERENCE.md) for complete API documentation including:
+- All endpoints with request/response examples
+- Bruno v3.0 test collections for all endpoints
+- Error handling details
+- Authentication & security features
+
+### Device Setup Guides
+- [KOBOREADER_SETUP.md](KOBOREADER_SETUP.md) - KOReader device configuration
+- [KOBO_SETUP.md](KOBO_SETUP.md) - Kobo device configuration
+
+### Universal Sync Documentation
+- [UNIVERSAL_SYNC_IMPLEMENTATION_GUIDE.md](UNIVERSAL_SYNC_IMPLEMENTATION_GUIDE.md) - Complete sync architecture
 
 ### Error Handling
 All API endpoints return standardized error responses: