fix(AdminService, AdminController): enhance error handling and character deletion logic

- Updated error handling in AdminController to include 'targetnotdead' status for improved response accuracy.
- Modified character deletion logic in AdminService to ensure correct target character is identified, especially when dealing with living characters, enhancing data integrity during cleanup operations.
- Adjusted attributes fetched for characters to include 'health', facilitating better decision-making in deletion processes.

backend/controllers/adminController.js

@@ -518,7 +518,7 @@ class AdminController {
             console.log(error);
             const status = error.message === 'noaccess'
                 ? 403
-                : (['invalidCharacter', 'notfound'].includes(error.message) ? 400 : 500);
+                : (['invalidCharacter', 'notfound', 'targetnotdead'].includes(error.message) ? 400 : 500);
             res.status(status).json({ error: error.message });
         }
     }