获取文档列表

{
    "documents": [
        {
            "document_id": 1,
            "filename": "机器学习入门.pdf",
            "file_type": "pdf",
            "file_size": 2097152,
            "status": "completed",
            "chunk_count": 45,
            "error_message": null,
            "created_at": "2024-01-15T10:30:00Z",
            "updated_at": "2024-01-15T10:32:00Z"
        },
        {
            "document_id": 2,
            "filename": "深度学习笔记.pdf",
            "file_type": "pdf",
            "file_size": 1048576,
            "status": "processing",
            "chunk_count": null,
            "error_message": null,
            "created_at": "2024-01-15T11:00:00Z",
            "updated_at": "2024-01-15T11:00:00Z"
        }
    ],
    "total": 2
}