fix: keep birthdays and show Shamsi dates

Imported customers keep their birthday, and assistant text plus remaining calendars use the Jalali date.

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

apps/api/src/integrations/tahesab/tahesab.module.ts

@@ -3,7 +3,10 @@ import { AuthModule } from '../../auth/auth.module';
 import { TahesabCryptoService } from './tahesab-crypto.service';
 import { TahesabHttpClient } from './tahesab-http.client';
 import { TahesabConnectionsService } from './connections.service';
-import { TahesabPersonLinkService } from './person-link.service';
+import {
+  TahesabBirthDateBackfill,
+  TahesabPersonLinkService,
+} from './person-link.service';
 import { TahesabProductLinkService } from './product-link.service';
 import { TahesabBalanceService } from './balance.service';
 import { TahesabDocumentsService } from './documents.service';
@@ -17,6 +20,7 @@ import { TahesabController } from './tahesab.controller';
     TahesabHttpClient,
     TahesabConnectionsService,
     TahesabPersonLinkService,
+    TahesabBirthDateBackfill,
     TahesabProductLinkService,
     TahesabBalanceService,
     TahesabDocumentsService,