feat: refactor: change image generation quality

- Modify the code to use the `hd` quality setting
- Update the code to use the `hd` quality setting.
- Ensure there are no other side effects of this change.
- These changes will improve the user experience.
</commit_message>

app/services/ai_service.rb

@@ -35,7 +35,8 @@ class AiService
         model: "dall-e-3",
         prompt: prompt,
         size: "1792x1024",
-        quality: "standard",
+        # quality: "standard",
+        quality: "hd",
         n: 1
       }
     )