Add internal org chat (phase 1) with DM, groups, and org settings.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/prisma/schema.prisma

@@ -207,6 +207,8 @@ model Organization {
   leadStages             LeadStage[]
   leadEvents             LeadEvent[]
   leadImportJobs         LeadImportJob[]
+  conversationSettings   ConversationSettings?
+  conversationRooms      ConversationRoom[]
 }
 
 model User {
@@ -2060,3 +2062,36 @@ model LeadImportJob {
   @@index([organizationId, status, createdAt])
   @@index([status, createdAt])
 }
+
+/// تنظیمات اتصال به سرویس گفتگوی خارجی (هر محیط CRM)
+model ConversationSettings {
+  organizationId String       @id
+  organization   Organization @relation(fields: [organizationId], references: [id], onDelete: Cascade)
+  chatHost       String
+  apiKeyCipher   String
+  apiKeyIv       String
+  apiKeyTag      String
+  uploadUrl      String       @default("")
+  downloadUrl    String       @default("")
+  createdAt      DateTime     @default(now())
+  updatedAt      DateTime     @updatedAt
+}
+
+/// نگاشت roomهای سرویس چت (DM dedup و گروه‌های ساخته‌شده از CRM)
+model ConversationRoom {
+  id              String       @id @default(cuid())
+  organizationId  String
+  organization    Organization @relation(fields: [organizationId], references: [id], onDelete: Cascade)
+  externalRoomId  String
+  kind            String
+  name            String?
+  dmUserMinId     String?
+  dmUserMaxId     String?
+  createdByUserId String?
+  createdAt       DateTime     @default(now())
+  updatedAt       DateTime     @updatedAt
+
+  @@unique([organizationId, externalRoomId])
+  @@unique([organizationId, dmUserMinId, dmUserMaxId])
+  @@index([organizationId, kind])
+}