Fix Azure SDK API compilation errors and enable Portal execution

- Fix Pageable<GenericResource> to use foreach instead of await foreach
- Fix AzureLocation access pattern to remove null coalescing operator
- Add missing _armClient field and Azure.Core using statement in CosmosDiscoveryService
- Add proper ResourceIdentifier usage for subscription access
- Portal now runs successfully on port 5010
- All live data discovery services compile and execute properly

Author: srnichols

management-portal/src/Portal/Services/AzureInfrastructureService.cs

@@ -62,14 +62,14 @@ public async Task<InfrastructureDiscoveryResult> DiscoverInfrastructureAsync()
 
                                 // Get all resources in this resource group
                                 var rgResources = resourceGroup.GetGenericResources();
-                                await foreach (var resource in rgResources)
+                                foreach (var resource in rgResources)
                                 {
                                     var discoveredResource = new DiscoveredResource
                                     {
                                         Id = resource.Id.ToString(),
                                         Name = resource.Data.Name,
                                         Type = resource.Data.ResourceType.ToString(),
-                                        Location = resource.Data.Location?.Name ?? "unknown",
+                                        Location = resource.Data.Location.Name,
                                         ResourceGroup = resourceGroup.Data.Name
                                     };
                                     resources.Add(discoveredResource);
@@ -148,7 +148,7 @@ private bool IsStampsResourceGroup(string resourceGroupName)
             var resourceCount = 0;
 
             var resources = resourceGroup.GetGenericResources();
-            await foreach (var resource in resources)
+            foreach (var resource in resources)
             {
                 resourceCount++;
                 var resourceType = resource.Data.ResourceType.ToString();

management-portal/src/Portal/Services/CosmosDiscoveryService.cs

@@ -2,6 +2,7 @@
 using Azure.Identity;
 using Azure.ResourceManager;
 using Azure.ResourceManager.Resources;
+using Azure.Core;
 
 namespace Stamps.ManagementPortal.Services;
 
@@ -17,6 +18,7 @@ public class CosmosDiscoveryService : ICosmosDiscoveryService
     private readonly ILogger<CosmosDiscoveryService> _logger;
     private readonly IConfiguration _configuration;
     private readonly IDataService _dataService;
+    private readonly ArmClient _armClient;
 
     public CosmosDiscoveryService(
         ILogger<CosmosDiscoveryService> logger, 
@@ -26,6 +28,7 @@ public CosmosDiscoveryService(
         _logger = logger;
         _configuration = configuration;
         _dataService = dataService;
+        _armClient = new ArmClient(new DefaultAzureCredential());
     }
 
     public async Task<List<Tenant>> DiscoverTenantsAsync()
@@ -312,10 +315,11 @@ private async Task<string> DetermineCellId(ResourceGroupResource resourceGroup)
     {
         // Look for related cell/stamp resource groups in the same region
         var location = resourceGroup.Data.Location.Name;
-        var subscription = resourceGroup.Parent;
+        var subscriptionId = resourceGroup.Id.SubscriptionId;
+        var subscription = _armClient.GetSubscriptionResource(new ResourceIdentifier($"/subscriptions/{subscriptionId}"));
 
         var resourceGroups = subscription.GetResourceGroups();
-        await foreach (var rg in resourceGroups)
+        foreach (var rg in resourceGroups)
         {
             if (IsCellResourceGroup(rg.Data.Name) && rg.Data.Location.Name == location)
             {
@@ -363,7 +367,7 @@ private async Task<string> DetermineCellHealth(ResourceGroupResource resourceGro
             var resourceCount = 0;
             var criticalResourceCount = 0;
 
-            await foreach (var resource in resources)
+            foreach (var resource in resources)
             {
                 resourceCount++;
                 var resourceType = resource.Data.ResourceType.ToString();
@@ -396,7 +400,7 @@ private async Task<string> DetermineCellHealth(ResourceGroupResource resourceGro
             var resources = resourceGroup.GetGenericResources();
             var resourceCount = 0;
 
-            await foreach (var resource in resources)
+            foreach (var resource in resources)
             {
                 resourceCount++;
             }