Align companies with the Didar export: new fields, Didar-format Excel import/export, and people linked to companies by Didar code

apps/api/prisma/schema.prisma

@@ -398,12 +398,28 @@ model Company {
   organizationId String
   organization   Organization @relation(fields: [organizationId], references: [id], onDelete: Cascade)
   name           String
+  /// کد داخلی شرکت (مثل «کد شرکت» در دیدار)
+  code           String?
+  /// منبع ورود: manual | didar | tahesab | excel | other
+  importSource   String       @default("manual")
+  /// شناسه در مبدأ (مثلاً کد دیدار شرکت)
+  sourceRef      String?
   nationalId     String?
+  economicCode   String?
+  registrationNumber String?
   phone          String?
+  otherPhones    String?
+  fax            String?
   email          String?
+  otherEmails    String?
   website        String?
+  province       String?
+  city           String?
+  postalCode     String?
   address        String?
+  groupName      String?
   notes          String?
+  registeredAt   DateTime?
   tags           String[]     @default([])
   customFields   Json         @default("{}")
   people         Person[]
@@ -423,6 +439,8 @@ model Company {
   @@index([organizationId, name])
   @@index([organizationId, email])
   @@index([organizationId, phone])
+  @@index([organizationId, sourceRef])
+  @@index([organizationId, code])
   @@index([ownerId])
 }