curl --request GET \
  --url https://api.digitalreceiptprotocol.org/api/v1/keys/escrow

{
  "success": true,
  "data": {
    "keyId": "550e8400-e29b-41d4-a716-446655440000",
    "publicKey": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8A...",
    "userId": "550e8400-e29b-41d4-a716-446655440001",
    "algorithm": "RSA-OAEP-256",
    "status": "active",
    "createdAt": "2025-12-15T12:00:00Z",
    "rotatedAt": null
  }
}