curl -X POST "https://api.stablepay.global/v2/users/{userId}/kyc/document" \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"documentType": "passport",
"s3Key": "kyc/user_123/passport/abc-def-ghi.pdf",
"fileName": "passport_scan.pdf",
"fileSize": 2048576,
"mimeType": "application/pdf",
"deviceId": "device_abc123"
}'