chore(codebase): full cleanup pass

backend/Modules/Messaging/Handlers/GetMessagesByUser.cs

@@ -30,16 +30,16 @@ public class GetMessagesByUser(
         GetMessagesByUserRequest req,
         CancellationToken ct)
     {
-        var messages = await context
+        List<Message> messages = await context
             .Messages
             .Where(c => c.CreatedBy == req.UserId)
             .Where(c => c.ParentId == null)
-            .ToListAsync(cancellationToken: ct);
+            .ToListAsync(ct);
 
-        var result = await Task.WhenAll(
+        MessageDto[] result = await Task.WhenAll(
             messages.Select(async message =>
             {
-                var user = await userLookup.GetUserAsync(message.CreatedBy, ct);
+                UserReference? user = await userLookup.GetUserAsync(message.CreatedBy, ct);
 
                 return new MessageDto
                 {