Refactor various services and models for improved type handling and configuration management

app/Services/QuickReplyResolver.php

@@ -17,9 +17,11 @@ class QuickReplyResolver
             $article->load('quickReplies');
         }
 
-        return $article->quickReplies
+        $quickReply = $article->quickReplies
             ->where('is_active', true)
             ->sortBy('title')
             ->first();
+
+        return $quickReply instanceof QuickReply ? $quickReply : null;
     }
 }