[BUG] ContainerService managedClusters/agentPools

### API Spec link

https://github.com/Azure/azure-rest-api-specs/blob/main/specification/containerservice/resource-manager/Microsoft.ContainerService/aks/stable/2025-10-01/managedClusters.json

### API Spec version

2025-10-01

### Describe the bug

In the agent pool security profile, `sshAccess` is not recognised by the RP:

```text
{
"code": "UnmarshalError",
"details": null,
"message": "UnmarshalEntity encountered error: json: unknown field \"sshAccess\" Check that the field is in the right location, is spelled correctly, and is supported in the API version. Visit aka.ms/aks/apiversions for more API version information..",
"subcode": ""
}
```

The docs state that this is the correct key name:

https://learn.microsoft.com/en-us/azure/templates/microsoft.containerservice/2025-10-01/managedclusters?pivots=deployment-language-terraform

https://github.com/Azure/azure-rest-api-specs/blob/2d03e26f69760a52d120a67ff9e4aac6916bc1c8/specification/containerservice/resource-manager/Microsoft.ContainerService/aks/stable/2025-10-01/managedClusters.json#L4595

### Expected behavior

securityProfile.sshAccess is correctly deserialized and set in the resource.

### Actual behavior

JSON unmarshal error from RP

### Reproduction Steps

PUT agentPool with securityProfile.sshAccess set to "LocalUser"

### Environment

Error surfaced via Microsoft's AzAPI Terraform provider (a low level REST API provider)

Start with the linked specification/containerservice/resource-manager/Microsoft.ContainerService/aks/stable/2025-10-01/managedClusters.json file and inspect the agent pool security profile around line 4595. Compare the documented sshAccess field with the API payload and related source definitions, then verify a PUT using securityProfile.sshAccess set to LocalUser no longer produces an unknown-field unmarshal error.

Written by the indexing model from the issue text.