Refactor N8n integration: update schema exports, improve import order, and enhance service logic

- Added export for N8n schema in chatbot.schema.ts.
- Improved import order in n8n.dto.ts and n8n.router.ts for better readability.
- Refactored variable declarations in n8n.service.ts for consistency and clarity.

src/api/integrations/chatbot/n8n/dto/n8n.dto.ts

@@ -1,4 +1,4 @@
-import { TriggerType, TriggerOperator } from '@prisma/client';
+import { TriggerOperator, TriggerType } from '@prisma/client';
 
 export class N8nDto {
   enabled?: boolean;