Create a new scan for a repository and queue it for execution.
Required Scope: write:scan
Security: Repository ownership validation
Args: repo_id: Repository ID to scan request: Scan creation request with scan_type and active_models background_tasks: FastAPI background tasks auth: Authentication context
Returns: Created scan details with task ID
Raises: 400: Bad request (validation errors, including if scan is already running) 401: Unauthorized (invalid token/API key) 403: Forbidden (insufficient scope or repository not owned by user’s org) 404: Not found (repository not found) 500: Internal server error