feat(schema): Account model with AccountStatus enum, optional Group.accountId

Adds Account model (platform, jid, sessionPath, displayName, status) with
AccountStatus enum (ACTIVE/DISCONNECTED/BANNED) and optional accountId FK
on Group for multi-account WhatsApp session tracking.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/api/prisma/schema.prisma

@@ -4,7 +4,7 @@ generator client {
 
 datasource db {
   provider = "postgresql"
-  url      = env("DATABASE_URL")
+  url      = env("../../../DATABASE_URL")  
 }
 
 model Group {
@@ -14,6 +14,8 @@ model Group {
   name        String
   description String?
   isActive    Boolean  @default(true)
+  accountId   String?
+  account     Account? @relation(fields: [accountId], references: [id])
   createdAt   DateTime @default(now())
   updatedAt   DateTime @updatedAt
 
@@ -91,3 +93,23 @@ model ConsentRecord {
 
   @@unique([groupId, memberJid, consentType])
 }
+
+enum AccountStatus {
+  ACTIVE
+  DISCONNECTED
+  BANNED
+}
+
+model Account {
+  id          String        @id @default(cuid())
+  platform    String
+  jid         String
+  sessionPath String
+  displayName String?
+  status      AccountStatus @default(ACTIVE)
+  groups      Group[]
+  createdAt   DateTime      @default(now())
+  updatedAt   DateTime      @updatedAt
+
+  @@unique([platform, jid])
+}