Enhance NPC creation functionality and validation in Admin module

- Updated AdminController to validate the count parameter, ensuring it is between 1 and 500.
- Refactored NPC creation logic in AdminService to create NPCs for each city-title combination, improving efficiency.
- Enhanced frontend localization files to reflect changes in count descriptions and validation messages.
- Updated CreateNPCView to provide user guidance on count input and display detailed creation results.

backend/controllers/adminController.js

@@ -389,13 +389,17 @@ class AdminController {
         try {
             const { userid: userId } = req.headers;
             const { regionIds, minAge, maxAge, minTitleId, maxTitleId, count } = req.body;
+            const countValue = parseInt(count) || 1;
+            if (countValue < 1 || countValue > 500) {
+                return res.status(400).json({ error: 'Count must be between 1 and 500' });
+            }
             const result = await AdminService.createNPCs(userId, {
                 regionIds: regionIds && regionIds.length > 0 ? regionIds : null,
                 minAge: parseInt(minAge) || 0,
                 maxAge: parseInt(maxAge) || 100,
                 minTitleId: parseInt(minTitleId) || 1,
                 maxTitleId: parseInt(maxTitleId) || 19,
-                count: parseInt(count) || 1
+                count: countValue
             });
             res.status(200).json(result);
         } catch (error) {