feat(msk-alpha): support Kafka 4.1 (#35759)

### Issue # (if applicable)

N/A
### Reason for this change
To support new Kafka version.

[Amazon MSK adds support for Apache Kafka version 4.1
](https://aws.amazon.com/about-aws/whats-new/2025/10/amazon-msk-apache-kafka-version-4-1/)



### Description of changes
Added ver 4.1 enum.


### Describe any new or updated permissions being added
N/A



### Description of how you validated changes
Add a unit test and an integ test.


### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: mazyu36

packages/@aws-cdk/aws-msk-alpha/README.md

@@ -23,7 +23,7 @@ The following example creates an MSK Cluster.
 declare const vpc: ec2.Vpc;
 const cluster = new msk.Cluster(this, 'Cluster', {
   clusterName: 'myCluster',
-  kafkaVersion: msk.KafkaVersion.V4_0_X_KRAFT,
+  kafkaVersion: msk.KafkaVersion.V4_1_X_KRAFT,
   vpc,
 });
 ```
@@ -36,7 +36,7 @@ To control who can access the Cluster, use the `.connections` attribute. For a l
 declare const vpc: ec2.Vpc;
 const cluster = new msk.Cluster(this, 'Cluster', {
   clusterName: 'myCluster',
-  kafkaVersion: msk.KafkaVersion.V4_0_X_KRAFT,
+  kafkaVersion: msk.KafkaVersion.V4_1_X_KRAFT,
   vpc,
 });
 
@@ -88,7 +88,7 @@ import * as acmpca from 'aws-cdk-lib/aws-acmpca';
 declare const vpc: ec2.Vpc;
 const cluster = new msk.Cluster(this, 'Cluster', {
   clusterName: 'myCluster',
-  kafkaVersion: msk.KafkaVersion.V4_0_X_KRAFT,
+  kafkaVersion: msk.KafkaVersion.V4_1_X_KRAFT,
   vpc,
   encryptionInTransit: {
     clientBroker: msk.ClientBrokerEncryption.TLS,
@@ -113,7 +113,7 @@ Enable client authentication with [SASL/SCRAM](https://docs.aws.amazon.com/msk/l
 declare const vpc: ec2.Vpc;
 const cluster = new msk.Cluster(this, 'cluster', {
   clusterName: 'myCluster',
-  kafkaVersion: msk.KafkaVersion.V4_0_X_KRAFT,
+  kafkaVersion: msk.KafkaVersion.V4_1_X_KRAFT,
   vpc,
   encryptionInTransit: {
     clientBroker: msk.ClientBrokerEncryption.TLS,
@@ -132,7 +132,7 @@ Enable client authentication with [IAM](https://docs.aws.amazon.com/msk/latest/d
 declare const vpc: ec2.Vpc;
 const cluster = new msk.Cluster(this, 'cluster', {
   clusterName: 'myCluster',
-  kafkaVersion: msk.KafkaVersion.V4_0_X_KRAFT,
+  kafkaVersion: msk.KafkaVersion.V4_1_X_KRAFT,
   vpc,
   encryptionInTransit: {
     clientBroker: msk.ClientBrokerEncryption.TLS,
@@ -155,7 +155,7 @@ import * as acmpca from 'aws-cdk-lib/aws-acmpca';
 declare const vpc: ec2.Vpc;
 const cluster = new msk.Cluster(this, 'Cluster', {
   clusterName: 'myCluster',
-  kafkaVersion: msk.KafkaVersion.V4_0_X_KRAFT,
+  kafkaVersion: msk.KafkaVersion.V4_1_X_KRAFT,
   vpc,
   encryptionInTransit: {
     clientBroker: msk.ClientBrokerEncryption.TLS,
@@ -186,7 +186,7 @@ declare const vpc: ec2.Vpc;
 declare const bucket: s3.IBucket;
 const cluster = new msk.Cluster(this, 'cluster', {
   clusterName: 'myCluster',
-  kafkaVersion: msk.KafkaVersion.V4_0_X_KRAFT,
+  kafkaVersion: msk.KafkaVersion.V4_1_X_KRAFT,
   vpc,
   logging: {
     s3: {
@@ -226,7 +226,7 @@ declare const bucket: s3.IBucket;
 
 const cluster = new msk.Cluster(this, 'cluster', {
   clusterName: 'myCluster',
-  kafkaVersion: msk.KafkaVersion.V4_0_X_KRAFT,
+  kafkaVersion: msk.KafkaVersion.V4_1_X_KRAFT,
   vpc,
   storageMode: msk.StorageMode.TIERED,
 });

packages/@aws-cdk/aws-msk-alpha/lib/cluster-version.ts

@@ -232,6 +232,13 @@ export class KafkaVersion {
    */
   public static readonly V4_0_X_KRAFT = KafkaVersion.of('4.0.x.kraft', { tieredStorage: true });
 
+  /**
+   * Kafka version 4.1.x with KRaft (Apache Kafka Raft) metadata mode support
+   *
+   * @see https://docs.aws.amazon.com/msk/latest/developerguide/metadata-management.html#kraft-intro
+   */
+  public static readonly V4_1_X_KRAFT = KafkaVersion.of('4.1.x.kraft', { tieredStorage: true });
+
   /**
    * Custom cluster version
    * @param version custom version number

packages/@aws-cdk/aws-msk-alpha/test/cluster.test.ts

@@ -52,6 +52,7 @@ describe('MSK Cluster', () => {
     [msk.KafkaVersion.V3_9_X, '3.9.x'],
     [msk.KafkaVersion.V3_9_X_KRAFT, '3.9.x.kraft'],
     [msk.KafkaVersion.V4_0_X_KRAFT, '4.0.x.kraft'],
+    [msk.KafkaVersion.V4_1_X_KRAFT, '4.1.x.kraft'],
   ],
   )('created with expected Kafka version %j', (parameter, result) => {
     new msk.Cluster(stack, 'Cluster', {