feat: Add NATS integration support to the event system

- Added NATS package to dependencies
- Created Prisma schema models for NATS configuration
- Implemented NATS controller, router, and event management
- Updated instance controller and event manager to support NATS
- Added NATS configuration options in environment configuration
- Included NATS events in instance validation schema

prisma/postgresql-schema.prisma

@@ -86,6 +86,7 @@ model Instance {
   Proxy                   Proxy?
   Setting                 Setting?
   Rabbitmq                Rabbitmq?
+  Nats                    Nats?
   Sqs                     Sqs?
   Websocket               Websocket?
   Typebot                 Typebot[]
@@ -125,6 +126,7 @@ model Chat {
   Instance       Instance  @relation(fields: [instanceId], references: [id], onDelete: Cascade)
   instanceId     String
   unreadMessages Int       @default(0)
+
   @@index([instanceId])
   @@index([remoteJid])
 }
@@ -168,6 +170,7 @@ model Message {
 
   sessionId String?
   session   IntegrationSession? @relation(fields: [sessionId], references: [id])
+
   @@index([instanceId])
 }
 
@@ -183,6 +186,7 @@ model MessageUpdate {
   messageId   String
   Instance    Instance @relation(fields: [instanceId], references: [id], onDelete: Cascade)
   instanceId  String
+
   @@index([instanceId])
   @@index([messageId])
 }
@@ -199,6 +203,7 @@ model Webhook {
   updatedAt       DateTime  @updatedAt @db.Timestamp
   Instance        Instance  @relation(fields: [instanceId], references: [id], onDelete: Cascade)
   instanceId      String    @unique
+
   @@index([instanceId])
 }
 
@@ -269,6 +274,7 @@ model Setting {
   updatedAt       DateTime  @updatedAt @db.Timestamp
   Instance        Instance  @relation(fields: [instanceId], references: [id], onDelete: Cascade)
   instanceId      String    @unique
+
   @@index([instanceId])
 }
 
@@ -282,6 +288,16 @@ model Rabbitmq {
   instanceId String    @unique
 }
 
+model Nats {
+  id         String    @id @default(cuid())
+  enabled    Boolean   @default(false) @db.Boolean
+  events     Json      @db.JsonB
+  createdAt  DateTime? @default(now()) @db.Timestamp
+  updatedAt  DateTime  @updatedAt @db.Timestamp
+  Instance   Instance  @relation(fields: [instanceId], references: [id], onDelete: Cascade)
+  instanceId String    @unique
+}
+
 model Sqs {
   id         String    @id @default(cuid())
   enabled    Boolean   @default(false) @db.Boolean