Updates managed item cache after retrieval

Ensures the local cache of managed certificate items
is updated whenever an item is retrieved. This helps
keep the cache synchronized with the actual state.

Author: webprofusion-chrisc

src/Certify.Server/Certify.Server.Hub.Api/Services/ManagementAPI.cs

@@ -160,7 +160,15 @@ private async Task SendCommandWithNoResult(string instanceId, InstanceCommandReq
                         new("managedCertId", managedCertId)
                     };
 
-            return await PerformInstanceCommandTaskWithResult<ManagedCertificate?>(instanceId, args, ManagementHubCommands.GetManagedItem);
+            var result = await PerformInstanceCommandTaskWithResult<ManagedCertificate?>(instanceId, args, ManagementHubCommands.GetManagedItem);
+
+            if (result != null)
+            {
+                // update local cache
+                _mgmtStateProvider.UpdateCachedManagedInstanceItem(instanceId, result);
+            }
+
+            return result;
         }
 
         /// <summary>