feat(tahesab): import and refresh customers at chosen hours

Each connection can set how many times a day and at which Tehran hours the server pulls Tahesab customers, including name updates for people already linked.

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

apps/api/prisma/migrations/20261105140000_tahesab_customer_sync_hours/migration.sql

@@ -0,0 +1,6 @@
+ALTER TABLE "AccountingConnection"
+  ADD COLUMN "customerSyncHours" INTEGER[] NOT NULL DEFAULT ARRAY[]::INTEGER[],
+  ADD COLUMN "customerSyncLastSlot" TEXT,
+  ADD COLUMN "customerSyncLastRunAt" TIMESTAMP(3),
+  ADD COLUMN "customerSyncLastSummary" TEXT,
+  ADD COLUMN "customerSyncLastError" TEXT;

apps/api/prisma/schema.prisma

@@ -1843,6 +1843,13 @@ model AccountingConnection {
   lastHealthAt     DateTime?
   lastHealthOk     Boolean?
   lastError        String?
+  /// ساعت‌های بروزرسانی خودکار مشتریان (۰ تا ۲۳، وقت تهران). خالی یعنی خاموش.
+  customerSyncHours       Int[]     @default([])
+  /// نوبت claimشده، مثل 2026-11-05-08، تا در همان ساعت دو بار اجرا نشود
+  customerSyncLastSlot    String?
+  customerSyncLastRunAt   DateTime?
+  customerSyncLastSummary String?
+  customerSyncLastError   String?
   createdAt        DateTime                 @default(now())
   updatedAt        DateTime                 @updatedAt
   personLinks      PersonAccountingLink[]