Add kaigen debit credit for backtest

docs/KaigenConfiguration.md

@@ -0,0 +1,64 @@
+# Kaigen Service Configuration
+
+The Kaigen service is used for managing user credits during backtest operations. It requires proper configuration to function correctly.
+
+## Environment Variables
+
+### Required Environment Variable
+
+- **`KAIGEN_PRIVATE_KEY`**: The private key used for signing API requests to the Kaigen service.
+
+### Setting the Environment Variable
+
+#### Development
+```bash
+export KAIGEN_PRIVATE_KEY="your-private-key-here"
+```
+
+#### Production
+Set the environment variable in your deployment configuration:
+```bash
+KAIGEN_PRIVATE_KEY=your-private-key-here
+```
+
+#### Docker
+```bash
+docker run -e KAIGEN_PRIVATE_KEY=your-private-key-here your-app
+```
+
+#### Docker Compose
+```yaml
+environment:
+  - KAIGEN_PRIVATE_KEY=your-private-key-here
+```
+
+## Configuration Structure
+
+The Kaigen service configuration is defined in `appsettings.json`:
+
+```json
+{
+  "Kaigen": {
+    "BaseUrl": "https://api.kaigen.managing.live",
+    "DebitEndpoint": "/api/credits/debit",
+    "RefundEndpoint": "/api/credits/refund",
+    "PrivateKey": "${KAIGEN_PRIVATE_KEY}"
+  }
+}
+```
+
+## API Endpoints
+
+- **PUT** `/api/credits/debit` - Debit credits from user account
+- **PUT** `/api/credits/refund` - Refund credits to user account
+
+## Security Notes
+
+- The private key should never be committed to source control
+- Use environment variables or secure configuration management systems
+- The private key is used for signing API requests to ensure authenticity
+- Rotate the private key regularly for enhanced security
+
+## Error Handling
+
+If the `KAIGEN_PRIVATE_KEY` environment variable is not set, the application will throw an `InvalidOperationException` with a clear error message during startup.