List support documents

{
    "success": true,
    "data": [
        {
            "id": "doc_abc123xyz",
            "document_type": "contract",
            "name": "Service Contract.pdf",
            "description": "Main service contract for consulting services",
            "file_url": "https://storage.googleapis.com/...",
            "file_name": "contract.pdf",
            "file_size": 245680,
            "mime_type": "application/pdf",
            "compliance_status": "pending_review",
            "compliance_notes": "string",
            "valid_from": 0,
            "valid_until": 0,
            "ai_extraction": {
                "extracted_at": 0,
                "extracted_by": "ai",
                "model": "gemini-3-flash",
                "confidence": 0.95,
                "extracted_data": {
                    "property1": "string",
                    "property2": "string"
                },
                "warnings": [
                    "string"
                ]
            },
            "audits": [
                {
                    "context_type": "invoice",
                    "context_id": "string",
                    "audited_at": 0,
                    "result": "valid",
                    "summary": "string",
                    "details": {
                        "property1": "string",
                        "property2": "string"
                    }
                }
            ],
            "created_at": 1677651234000,
            "created_by": "user_abc123",
            "updated_at": 1677651234000,
            "linked_entities": [
                {
                    "entity_type": "invoice",
                    "entity_id": "string",
                    "linked_at": 0
                }
            ]
        }
    ],
    "message": "Support documents retrieved successfully",
    "timestamp": "2019-08-24T14:15:22.123Z"
}