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/src/modules/accounting-sync/providers/index.ts

@@ -0,0 +1,18 @@
+import { AccountingProvider, ProviderName } from './accounting-provider';
+import { tahesabProvider } from './tahesab.provider';
+import { zarrinProvider } from './zarrin.provider';
+
+/**
+ * Every accounting software, keyed by the admin switch's value. A new one is a
+ * driver file plus one line here — the same shape as the SMS drivers (D26).
+ */
+export const ACCOUNTING_PROVIDERS: Readonly<Record<ProviderName, AccountingProvider>> = {
+  tahesab: tahesabProvider,
+  zarrin: zarrinProvider,
+};
+
+export function isProviderName(v: unknown): v is ProviderName {
+  return typeof v === 'string' && Object.prototype.hasOwnProperty.call(ACCOUNTING_PROVIDERS, v);
+}
+
+export * from './accounting-provider';