Clarify Orleans constructor migration guidance (#52870)

* Clarify Orleans constructor migration guidance

Update the Orleans migration guide and breaking changes summary to distinguish serializer constructors from generated activator constructors.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Refine Orleans constructor migration docs

Clarify that the replacement attributes are for dependency injection scenarios and update the migration example to use an injected service instead of serialized data.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Mark injected dependency as non-serialized

Update the Orleans migration guide example so the injected dependency property is marked with [field: NonSerialized] and does not trigger analyzer warnings.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Clarify OrleansConstructor sample comment

Update the Orleans migration guide sample to note that [OrleansConstructor] was obsolete and ignored.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Update docs/orleans/migration-guide.md

Co-authored-by: Genevieve Warren <24882762+gewarren@users.noreply.github.com>

* Update docs/orleans/includes/orleans-10-breaking-changes.md

Co-authored-by: Genevieve Warren <24882762+gewarren@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Genevieve Warren <24882762+gewarren@users.noreply.github.com>

Author: 3 people

docs/orleans/includes/orleans-10-breaking-changes.md

@@ -10,5 +10,5 @@
 | `CancelRequestOnTimeout` default changed | Behavioral | Explicitly set to `true` if needed |
 | ADO.NET provider requires `Microsoft.Data.SqlClient` | Compile/Runtime error | Replace `System.Data.SqlClient` package |
 | `[Unordered]` attribute obsoleted | Warning | Remove attribute (has no effect) |
-| `OrleansConstructorAttribute` obsoleted | Warning | Use <xref:Orleans.GeneratedActivatorConstructorAttribute> |
+| `OrleansConstructorAttribute` obsoleted | Warning | Use <xref:Orleans.GeneratedActivatorConstructorAttribute> or <xref:Microsoft.Extensions.DependencyInjection.ActivatorUtilitiesConstructorAttribute> only for constructors that require dependency injection, not for serialized data properties |
 | `RegisterTimer` obsoleted | Warning | Use <xref:Orleans.GrainBaseExtensions.RegisterGrainTimer*> |

docs/orleans/migration-guide.md

@@ -156,23 +156,45 @@ public interface IMyGrain : IGrainWithStringKey
 
 ### Breaking change: `OrleansConstructorAttribute` obsoleted
 
-The `OrleansConstructorAttribute` has been obsoleted. Use <xref:Orleans.GeneratedActivatorConstructorAttribute> or `ActivatorUtilitiesConstructorAttribute` instead to specify which constructor the serializer should use.
+The `OrleansConstructorAttribute` has been obsoleted. Use <xref:Orleans.GeneratedActivatorConstructorAttribute> or <xref:Microsoft.Extensions.DependencyInjection.ActivatorUtilitiesConstructorAttribute> instead. Only apply these attributes to constructors that require services to be injected via dependency injection. Don't use them to indicate how Orleans should set serialized data properties or fields.
 
 ```csharp
+public interface IMyDependency
+{
+}
+
 // Orleans 7.x
 [GenerateSerializer]
 public class MyClass
 {
-    [OrleansConstructor] // Obsolete
-    public MyClass(string value) { }
+    [Id(0)]
+    public string Value { get; set; }
+
+    [OrleansConstructor] // Obsolete and ignored
+    public MyClass(IMyDependency dependency)
+    {
+        Dependency = dependency;
+    }
+
+    [field: NonSerialized]
+    public IMyDependency Dependency { get; }
 }
 
 // Orleans 10.0
 [GenerateSerializer]
 public class MyClass
 {
+    [Id(0)]
+    public string Value { get; set; }
+
     [GeneratedActivatorConstructor]
-    public MyClass(string value) { }
+    public MyClass(IMyDependency dependency)
+    {
+        Dependency = dependency;
+    }
+
+    [field: NonSerialized]
+    public IMyDependency Dependency { get; }
 }
 ```