Implement Sprint 2: Source Management
- Add SourceService with create, list, delete, research methods
- Add POST /api/v1/notebooks/{id}/sources - Add source (URL, YouTube, Drive)
- Add GET /api/v1/notebooks/{id}/sources - List sources with filtering
- Add DELETE /api/v1/notebooks/{id}/sources/{source_id} - Delete source
- Add POST /api/v1/notebooks/{id}/sources/research - Web research
- Add ResearchRequest model for research parameters
- Integrate sources router with main app
Endpoints:
- POST /sources - 201 Created
- GET /sources - 200 OK with pagination
- DELETE /sources/{id} - 204 No Content
- POST /sources/research - 202 Accepted
Technical:
- Support for url, youtube, drive source types
- Filtering by source_type and status
- Validation for research mode (fast/deep)
- Error handling with standardized responses
Related: Sprint 2 - Source Management
