[docs] Document Azure Sandbox default compute environment inference

src/frontend/src/content/docs/deployment/azure/sandboxes.mdx

@@ -12,7 +12,7 @@ import LearnMore from '@components/LearnMore.astro';
 Use `aspire deploy` to deploy Aspire applications to [Azure Container Apps Sandboxes](https://sandboxes.azure.com/docs/sandboxes/quickstart/setup-portal). Aspire provisions a sandbox group, an Azure Container Registry, and the managed identities and role assignments the group needs. It then builds or resolves a container image for each compute resource and runs it as a sandbox with the lifecycle and endpoint settings you configure in your AppHost.
 
 :::caution[Preview service and prerelease package]
-Azure Container Apps Sandboxes is a preview Azure service, and the `Aspire.Hosting.Azure.Sandboxes` library is prerelease. The Sandbox APIs don't require an `ASPIREAZURE001` suppression. The Azure service isn't generally available, and the API surface and deployment behavior may change.
+Azure Container Apps Sandboxes is a preview Azure service, and the `Aspire.Hosting.Azure.Sandboxes` library is prerelease. The Azure service isn't generally available, and the API surface and deployment behavior may change.
 :::
 
 <LearnMore>

src/frontend/src/content/docs/whats-new/aspire-13-6.mdx

@@ -340,6 +340,8 @@ The service requires preview access in your Azure subscription and region. Refer
 
 The prerelease `Aspire.Hosting.Azure.Sandboxes` package adds Azure Container Apps Sandboxes as a deployment target. Add a sandbox group to your AppHost, and `aspire deploy` provisions the group, an Azure Container Registry, and the identities and role assignments the group needs. It then runs your project, container, and Dockerfile resources as isolated sandboxes. When the sandbox group is the only compute environment, Aspire assigns compute resources to it automatically.
 
+When an AppHost defines multiple compute environments, select the target sandbox group with `WithComputeEnvironment` / `withComputeEnvironment`. `PublishAsAzureSandbox` / `publishAsAzureSandbox` configures sandbox-specific runtime options without taking a sandbox-group parameter.
+
 Use `PublishAsAzureSandbox` / `publishAsAzureSandbox` to choose one of five resource tiers and to configure auto-suspend and auto-delete:
 
 <Tabs syncKey='aspire-lang'>
@@ -397,12 +399,11 @@ builder.Build().Run();
 </TabItem>
 </Tabs>
 
-Only endpoints marked external get a public HTTPS URL. Those URLs require Microsoft Entra ID authentication unless you opt in to anonymous access for a specific endpoint. Aspire resolves images to immutable Linux/amd64 digests and applies a deny-by-default egress policy. It also removes stale sandboxes and disk images on redeploy and on `aspire destroy`. For setup, identity, endpoint, and lifecycle details, see [Deploy to Azure Container Apps Sandboxes](/deployment/azure/sandboxes/).
+Only endpoints marked as external get a public HTTPS URL. Those URLs require Microsoft Entra ID authentication unless you opt in to anonymous access for a specific endpoint. Aspire resolves images to immutable Linux/amd64 digests and applies a deny-by-default egress policy. It also removes stale sandboxes and disk images on redeploy and on `aspire destroy`. For setup, identity, endpoint, and lifecycle details, see [Deploy to Azure Container Apps Sandboxes](/deployment/azure/sandboxes/).
 
 <Aside type="caution" title="Preview service">
   Azure Container Apps Sandboxes requires preview access in your Azure
   subscription and region, and its Aspire package remains prerelease.
-  The Sandbox APIs no longer require `ASPIREAZURE001` suppression in 13.6.
   The integration doesn't yet support volumes, TCP ports, private
   service discovery, or Windows and ARM64 images.
 </Aside>