chore(codebase): full cleanup pass

backend/Modules/Messaging/Handlers/DeleteMessage.cs

@@ -30,21 +30,21 @@ public class DeleteMessage(
         DeleteMessageRequest req,
         CancellationToken ct)
     {
-        var message = await context.Messages.FirstOrDefaultAsync(x => x.Id == req.MessageId, ct);
+        Message? message = await context.Messages.FirstOrDefaultAsync(x => x.Id == req.MessageId, ct);
 
         if (message is null)
         {
             await SendNotFoundAsync(ct);
             return;
         }
-        
-        var userId = HttpContext.User.GetUserId();
+
+        Guid userId = HttpContext.User.GetUserId();
         if (message.CreatedBy != userId)
         {
             await SendForbiddenAsync(ct);
             return;
         }
-        
+
         context.Messages.Remove(message);
 
         await context.SaveChangesAsync(ct);