Get active loans for a merchant

{
    "merchant": {
        "opensylo_id": "mch_a1b2c3d4-e5f6-7890-abcd-ef1234567890",
        "marketplace_id": "PLT_MERCH_001",
        "name": "Adebayo Electronics"
    },
    "active_loans": [
        {
            "loan_id": "loan_f1e2d3c4-b5a6-7890-1234-567890abcdef",
            "reference": "OSL-2026-00142",
            "lender": {
                "id": "lnd_abc123",
                "name": "Sterling MFB"
            },
            "status": "repaying",
            "disbursed_at": "2026-03-15T09:00:00.000Z",
            "due_date": "2026-09-15T09:00:00.000Z",
            "terms": {
                "principal_amount": 1500000,
                "total_repayment": 1725000,
                "currency": "NGN"
            },
            "repayment": {
                "deduction_percentage": 10,
                "minimum_deduction": 500,
                "total_repaid": 345000,
                "outstanding": 1380000,
                "is_overdue": false,
                "days_overdue": 0
            },
            "deduction_active": true
        }
    ],
    "summary": {
        "total_active_loans": 1,
        "total_outstanding": 1380000,
        "combined_deduction_percentage": 10
    },
    "timestamp": "2026-04-07T10:30:00.000Z"
}