fix(accounting): zarrin copy and sign notes match verified install

Zarrin v228 was tested on the real install (test account 953): negative
balance = owes, and temporary documents move the balance at once. Update
the admin copy and provider comments to match what was verified.

پنل: متن راهنمای زرین به‌روز شد: علامت مانده روی نصب واقعی بررسی شده است، و هشدار مربوط به ثبت سند موقت در «ثبت سفارش» اضافه شد.

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>

apps/api/src/modules/accounting-sync/providers/zarrin.provider.ts

@@ -32,9 +32,10 @@ import {
  * ACC-01: negative balance = owes; a «فاکتور موقت» moves the balance at once
  * (unlike Tahesab); listKarSakhte pages by 100 (pageNum); parvande opens with
  * a «مانده از قبل» row that is not a movement; goroohSakhte answers HTTP 400
- * with a good body; infogardeshsakhte answers malformed JSON. The writing
- * calls (addAccount, edithesab, foroushSakhte, hazfRadifSanad,
- * addFelezsakhteModel) are still unverified.
+ * with a good body; infogardeshsakhte answers malformed JSON. Writes verified
+ * the same day on test account 953 (addAccount, edithesab, foroushSakhte,
+ * hazfRadifSanad); only addFelezsakhteModel is untested. Re-test with
+ * scripts/test-accounting-zarrin.ts; the full list is in plan §13.
  *
  * Differences from Tahesab that shape the sync:
  *   * No idempotency key on foroushSakhte. A timed-out document call cannot be
@@ -270,7 +271,7 @@ function owesDelta(r: Record<string, unknown>) {
 }
 
 function signed(s: ProviderSettings, v: Prisma.Decimal) {
-  // Until checked on a real installation (plan §9) the sign is a setting.
+  // v228: negative = owes (the default). Kept a setting in case another install differs.
   return (s.balanceOwesWhen ?? 'negative') === 'negative' ? v.negated() : v;
 }
 
@@ -375,7 +376,7 @@ export const zarrinProvider: AccountingProvider = {
   async getChanges(s, cursor) {
     // parLastTenRadif without an account is the newest rows of the whole
     // journal; each row names its account (idHesab) and has an ascending idRadif.
-    // Not yet seen on a real install (ACC-01).
+    // Seen working on v228 (plan §13).
     const rows = listOf(await call(s, 'parLastTenRadif', { limit: CHANGE_WINDOW }));
     let maxId = 0;
     for (const r of rows) maxId = Math.max(maxId, Number(r.idRadif) || 0);