feat: accounting integration (D27), SMS relay driver (D26), rebuild user apps

- Add Tahesab/Zarrin accounting sync module with admin panel UI
- Add SMS relay driver as default provider, refactor SMS into driver pattern
- Update customer services, orders, products, and catalog queries
- Rebuild user-app and user-app-v2 dist assets
- Add Prisma migration for accounting tables
- Update docker-compose and env examples
- Update parity docs (DECISIONS, ISSUES, PROGRESS)

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

apps/api/prisma/schema.prisma

@@ -400,6 +400,14 @@ model Customer {
   goldDebtGrams        Decimal @default(0) @db.Decimal(14, 4) // legacy remain
   fiatDebtRial         Decimal @default(0) @db.Decimal(20, 2) // legacy rial_remain
 
+  /// Balance as last read from the accounting software (D27), in the app's own
+  /// sign convention (positive = owes). Shown to the customer when the
+  /// integration is on; the credit-limit check still uses goldDebtGrams above.
+  /// Null until the first successful sync.
+  accountingGoldBalance Decimal?  @db.Decimal(14, 4)
+  accountingRialBalance Decimal?  @db.Decimal(20, 2)
+  accountingBalanceAt   DateTime?
+
   /// Legacy `customers.percent` — the per-customer making-charge offset. It is
   /// ADDED to the variant's making charge when pricing an order line
   /// (henza_pwa src/Mixins/product/index.ts:69-75:
@@ -557,6 +565,14 @@ model Product {
   isActive    Boolean   @default(true)
   createdAt   DateTime  @default(now())
 
+  /// Stock of the linked کارساخته as last read from the accounting software
+  /// (D27). Weight for gram-type items, count for count-type ones — whichever
+  /// the software reports. At zero or below the product is unavailable in the
+  /// app (pre-order variants excepted). Null = not linked or never synced.
+  accountingStockWeight Decimal?  @db.Decimal(14, 4)
+  accountingStockCount  Decimal?  @db.Decimal(14, 4)
+  accountingStockAt     DateTime?
+
   variants        ProductVariant[]
   images          ProductImage[]
   collections     CollectionProduct[]
@@ -911,6 +927,115 @@ model Setting {
   updatedAt DateTime @updatedAt
 }
 
+// ─────────────────────────────────────────────────────────────────────────
+// Accounting integration (D27) — the shop's accounting software, Tahesab or
+// Zarrin, chosen in the admin panel. Configuration lives in the Setting row
+// `accounting.config` (never served by the generic `const` routes). Plan:
+// docs/ACCOUNTING-INTEGRATION-PLAN.md.
+//
+// `provider` is the driver name ('tahesab' | 'zarrin'), a plain string like
+// SMS_PROVIDER so a new driver needs no migration. Links are per provider, so
+// switching provider and back loses nothing.
+// ─────────────────────────────────────────────────────────────────────────
+
+enum AccountingEntityType {
+  CUSTOMER
+  PRODUCT
+}
+
+/// One app row ↔ one record in the accounting software (customer account or
+/// کارساخته).
+model AccountingLink {
+  id           String               @id @default(cuid())
+  provider     String
+  entityType   AccountingEntityType
+  entityId     String
+  /// The record's code in the accounting software (Tahesab Moshtari_Code /
+  /// Zarrin idHesab; for products the Zarrin idKar or the Tahesab Name_Kar).
+  externalCode String
+  externalName String?
+  /// How the link came to be: LINKED (matched by mobile/name), IMPORTED (app
+  /// row created from the accounting record), PUSHED (accounting record created
+  /// from the app row) or MANUAL (an admin typed the code).
+  origin       String
+  /// The record as last read, for display only.
+  snapshot     Json?
+  syncedAt     DateTime             @default(now())
+  createdAt    DateTime             @default(now())
+
+  @@unique([provider, entityType, entityId])
+  @@unique([provider, entityType, externalCode])
+  @@index([entityType, entityId])
+}
+
+enum AccountingOutboxKind {
+  CUSTOMER_PUSH
+  PRODUCT_PUSH
+  ORDER_DOCUMENT
+  ORDER_DOCUMENT_DELETE
+}
+
+enum AccountingOutboxStatus {
+  PENDING
+  /// A call was in flight. Found at startup, it means the process died mid-call
+  /// and the outcome is unknown — see AccountingOutboxWorker.
+  SENDING
+  SENT
+  FAILED
+  /// Unsafe to retry automatically (e.g. a Zarrin call timed out: Zarrin has no
+  /// idempotency key, so a blind retry could post the document twice).
+  NEEDS_REVIEW
+  /// Closed by an admin from the log screen.
+  RESOLVED
+}
+
+/// Work to push to the accounting software. Written in the SAME transaction as
+/// the change that causes it, so an outage of the accounting software never
+/// loses an event and never blocks the app.
+model AccountingOutbox {
+  id            String                 @id @default(cuid())
+  provider      String
+  kind          AccountingOutboxKind
+  entityId      String
+  status        AccountingOutboxStatus @default(PENDING)
+  attempts      Int                    @default(0)
+  nextAttemptAt DateTime               @default(now())
+  lastError     String?
+  /// What the accounting software returned as the document/record id.
+  externalRef   String?
+  /// Per-step progress of multi-call jobs (a Zarrin document is one call per
+  /// line), so a failure resumes where it stopped.
+  progress      Json?
+  /// Last request/response, for the log screen. Never contains the token.
+  lastRequest   Json?
+  lastResponse  Json?
+  sentAt        DateTime?
+  resolvedById  String?
+  createdAt     DateTime               @default(now())
+  updatedAt     DateTime               @updatedAt
+
+  @@index([status, nextAttemptAt])
+  @@index([kind, entityId])
+}
+
+/// Something a pull found that needs a human: an account with no mobile, two
+/// accounts sharing one mobile, a کارساخته group with no category mapping.
+model AccountingIssue {
+  id           String    @id @default(cuid())
+  provider     String
+  kind         String
+  externalCode String
+  entityId     String?
+  message      String
+  data         Json?
+  createdAt    DateTime  @default(now())
+  updatedAt    DateTime  @updatedAt
+  resolvedAt   DateTime?
+
+  @@unique([provider, kind, externalCode])
+  @@index([resolvedAt])
+}
+
 // ─────────────────────────────────────────────────────────────────────────
 // Promotions / discounts — legacy views/promotion/*, served by
 // PromotionController (`product/variant/promotion`). The redesigned schema had