Introduce constant for todo list registry id

Author: egil

orleans/JournaledTodoList/JournaledTodoList.WebApp/Constants.cs

@@ -1,4 +1,6 @@
 public static class Constants
 {
     public const string StateStorageProviderName = "StateStorage";
+
+    public const string TodoListRegistryId = "registry";
 }

orleans/JournaledTodoList/JournaledTodoList.WebApp/Grains/TodoListGrain.cs

@@ -87,7 +87,7 @@ public async Task SetNameAsync(string listName)
         // Publish list with new name to todo list registry.
         // The registry only cares about the id and name of the list,
         // so this is the only place where we need to interact with the registry.
-        var registry = GrainFactory.GetGrain<ITodoListRegistryGrain>("registry");
+        var registry = GrainFactory.GetGrain<ITodoListRegistryGrain>(Constants.TodoListRegistryId);
         await registry.RegisterTodoListAsync(new TodoListReference(this.GetPrimaryKeyString(), listName));
     }
 

orleans/JournaledTodoList/JournaledTodoList.WebApp/Services/TodoListService.cs

@@ -9,15 +9,15 @@ public class TodoListService(IGrainFactory grainFactory)
 {
     public async Task<IDisposable> SubscribeAsync(ITodoListRegistryObserver observer)
     {
-        var registryGrain = grainFactory.GetGrain<ITodoListRegistryGrain>("registry");
+        var registryGrain = grainFactory.GetGrain<ITodoListRegistryGrain>(Constants.TodoListRegistryId);
         var observerRef = grainFactory.CreateObjectReference<ITodoListRegistryObserver>(observer);
         await registryGrain.Subscribe(observerRef);
         return new Subscription(observerRef, registryGrain);
     }
 
     public Task<ImmutableArray<TodoListReference>> GetTodoListReferencesAsync()
     {
-        var registryGrain = grainFactory.GetGrain<ITodoListRegistryGrain>("registry");
+        var registryGrain = grainFactory.GetGrain<ITodoListRegistryGrain>(Constants.TodoListRegistryId);
         return registryGrain.GetAllTodoListsAsync();
     }