Add diagnostic logging when gRPC generated code not found

When AddGrpcFromConfiguration method is not found via reflection,
logs detailed diagnostics to help identify the root cause:
- Entry assembly name and total type count
- All Grpc-related types with their IsClass/IsSealed/IsPublic flags
- Whether the target method exists on each type
- ReflectionTypeLoadException details if type loading fails

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Svrnty.CQRS.Grpc/CqrsBuilderExtensions.cs

@@ -33,6 +33,7 @@ public static class CqrsBuilderExtensions
         {
             Console.WriteLine("Warning: AddGrpcFromConfiguration not found. gRPC services were not registered.");
             Console.WriteLine("Make sure your project has source generators enabled and references Svrnty.CQRS.Grpc.Generators.");
+            DiagnoseGeneratedCode();
         }
 
         // Register mapping callback for automatic endpoint mapping
@@ -49,6 +50,59 @@ public static class CqrsBuilderExtensions
         return builder;
     }
 
+    private static void DiagnoseGeneratedCode()
+    {
+        var entryAsm = Assembly.GetEntryAssembly();
+        if (entryAsm == null)
+        {
+            Console.WriteLine("Diagnostic: Entry assembly is null");
+            return;
+        }
+
+        Console.WriteLine($"Diagnostic: Entry assembly = {entryAsm.GetName().Name}");
+
+        try
+        {
+            var allTypes = entryAsm.GetTypes();
+            Console.WriteLine($"Diagnostic: Total types in entry assembly = {allTypes.Length}");
+
+            var grpcTypes = allTypes
+                .Where(t => t.FullName?.Contains("Grpc") == true)
+                .ToList();
+
+            if (grpcTypes.Any())
+            {
+                Console.WriteLine("Diagnostic: Found Grpc-related types:");
+                foreach (var t in grpcTypes)
+                {
+                    Console.WriteLine($"  - {t.FullName} (IsClass={t.IsClass}, IsSealed={t.IsSealed}, IsPublic={t.IsPublic})");
+
+                    // Check for our target method
+                    var method = t.GetMethod("AddGrpcFromConfiguration", BindingFlags.Static | BindingFlags.Public);
+                    if (method != null)
+                        Console.WriteLine($"    -> HAS AddGrpcFromConfiguration method!");
+                }
+            }
+            else
+            {
+                Console.WriteLine("Diagnostic: No Grpc-related types found. Source generator did NOT run.");
+            }
+        }
+        catch (ReflectionTypeLoadException ex)
+        {
+            Console.WriteLine($"Diagnostic: ReflectionTypeLoadException - {ex.Message}");
+            foreach (var le in ex.LoaderExceptions)
+            {
+                if (le != null)
+                    Console.WriteLine($"  LoaderException: {le.Message}");
+            }
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Diagnostic: Exception - {ex.GetType().Name}: {ex.Message}");
+        }
+    }
+
     private static MethodInfo? FindExtensionMethod(string methodName, Type parameterType)
     {
         // Search through all loaded assemblies for the extension method