feat: Integration with Dify

Adds support for Dify integration, including new routes, services, and controllers. The configuration for Dify has been added to the environment file, and the necessary changes have been made to the `.env.example` file. Additionally, the WhatsApp Baileys service has been updated to handle Dify notifications.

Modified files:
- `.env.example`
- `package.json`
- `src/api/integrations/openai/services/openai.service.ts`
- `src/api/routes/index.router.ts`
- `src/api/server.module.ts`
- `src/api/services/channel.service.ts`
- `src/api/services/channels/whatsapp.baileys.service.ts`
- `src/config/env.config.ts`
- `src/validate/validate.schema.ts`

Introduced files:
- `src/api/integrations/dify/`
- `src/api/integrations/dify/controllers/dify.controller.ts`
- `src/api/integrations/dify/dto/dify.dto.ts`
- `src/api/integrations/dify/routes/dify.router.ts`
- `src/api/integrations/dify/services/dify.service.ts`
- `src/api/integrations/dify/validate/dify.schema.ts`

src/api/services/channel.service.ts

@@ -26,6 +26,7 @@ import { SettingsDto } from '../dto/settings.dto';
 import { WebhookDto } from '../dto/webhook.dto';
 import { ChatwootDto } from '../integrations/chatwoot/dto/chatwoot.dto';
 import { ChatwootService } from '../integrations/chatwoot/services/chatwoot.service';
+import { DifyService } from '../integrations/dify/services/dify.service';
 import { OpenaiService } from '../integrations/openai/services/openai.service';
 import { RabbitmqDto } from '../integrations/rabbitmq/dto/rabbitmq.dto';
 import { getAMQP, removeQueues } from '../integrations/rabbitmq/libs/amqp.server';
@@ -71,6 +72,8 @@ export class ChannelStartupService {
 
   public openaiService = new OpenaiService(waMonitor, this.configService, this.prismaRepository);
 
+  public difyService = new DifyService(waMonitor, this.configService, this.prismaRepository);
+
   public setInstance(instance: InstanceDto) {
     this.logger.setInstance(instance.instanceName);