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/user-app/src/api/client.ts

@@ -294,6 +294,15 @@ export interface ReportBalance {
   arz: string;
   mandeh: string;
 }
+/** GET /customer/me/accounting-balance. Signed like the app: positive = owes. */
+export interface AccountingBalance {
+  source: 'accounting' | 'stored' | 'none'
+  gold: string | null
+  rial: string | null
+  at: string | null
+  provider: string | null
+}
+
 export const api = {
   listProducts: () => request<ProductSummary[]>('/catalog/products'),
 
@@ -323,6 +332,8 @@ export const api = {
   // /customers/:id, /:id/orders and /:id/ledger-entries, which took the id from
   // the URL and let anyone read anyone (SEC-08).
   getMe: () => request<CustomerDetail>('/customer/me'),
+  /** D27 §12 — this customer's balance, read from the accounting software on every call. */
+  getAccountingBalance: () => request<AccountingBalance>('/customer/me/accounting-balance'),
   getMyOrders: () => request<OrderDetail[]>('/customer/me/orders'),
   getMyLedgerEntries: () => request<LedgerEntrySummary[]>('/customer/me/ledger-entries'),