High-level VPC Gateway Attachment builder for connecting internet and VPN gateways to VPCs. **Use Cases: ** - Attach an Internet Gateway to enable internet access - Attach a Virtual Private Gateway for VPN connections **Rationale: ** Explicit gateway attachments provide fine-grained control over network connectivity and follow the principle of explicit configuration. **Escape Hatch: ** Access the underlying CDK VPCGatewayAttachment via the `Attachment` property for advanced scenarios not covered by this builder.