feat(cdk): add automatic Route 53 DNS record creation for custom domains

- Add Route 53 A record creation when custom domain is provided
- Update Python client setup to use --reinstall flag
- Remove CDK context file from version control
- Clean up gitignore formatting

Author: Jon Slominski

.gitignore

@@ -27,4 +27,5 @@ cdk.out
 .env
 **/.venv
 **/agentcore-gateway-and-runtime
-**/__pycache__
+**/__pycache__
+

README.md

@@ -196,7 +196,7 @@ The included Python client (`source/sample-clients/simple-auth-client-python/`)
 
    ```bash
    pip install uv
-   uv sync
+   uv sync --reinstall
    ```
 
 3. Set environment variables:

source/cdk/ecs-and-lambda/cdk.context.json

@@ -6,6 +6,8 @@ import * as elbv2 from "aws-cdk-lib/aws-elasticloadbalancingv2";
 import * as ecs from "aws-cdk-lib/aws-ecs";
 import * as acm from "aws-cdk-lib/aws-certificatemanager";
 import * as cloudfront from "aws-cdk-lib/aws-cloudfront";
+import * as route53 from "aws-cdk-lib/aws-route53";
+import * as route53targets from "aws-cdk-lib/aws-route53-targets";
 import * as ssm from "aws-cdk-lib/aws-ssm";
 import * as lambda from "aws-cdk-lib/aws-lambda";
 import * as origins from "aws-cdk-lib/aws-cloudfront-origins";
@@ -395,8 +397,28 @@ export class MCPServerStack extends cdk.Stack {
       },
     ]);
 
+    // Create Route 53 records if custom domain is provided
+    if (customDomain && certificateArn) {
+      // Look up the hosted zone
+      const hostedZone = route53.HostedZone.fromLookup(this, "HostedZone", {
+        domainName: customDomain,
+      });
+
+      // Create A record for the custom domain
+      new route53.ARecord(this, "McpServerARecord", {
+        zone: hostedZone,
+        recordName: customDomain,
+        target: route53.RecordTarget.fromAlias(
+          new route53targets.CloudFrontTarget(this.distribution)
+        ),
+      });
+    }
+
     // Set the HTTPS URL
-    const httpsUrl = `https://${this.distribution.distributionDomainName}`;
+    const httpsUrl =
+      customDomain && certificateArn
+        ? `https://${customDomain}`
+        : `https://${this.distribution.distributionDomainName}`;
 
     // Output CloudFront distribution details
     new cdk.CfnOutput(this, "CloudFrontDistributions", {