feat(api): .NET 10 multi-tenant REST API

Full backend implementation:
- Multi-tenant cafe/restaurant management (menus, orders, tables, staff)
- POS order flow with ZarinPal and Snappfood payment integration
- OTP authentication via Kavenegar SMS
- QR digital menu with public discover/finder endpoints
- Customer loyalty, coupons, CRM
- PostgreSQL via EF Core, Redis for caching/sessions
- Background jobs, webhook handlers
- Full migration history

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/Meezi.Core/Enums/UnifiedDeliveryStatus.cs

@@ -0,0 +1,12 @@
+namespace Meezi.Core.Enums;
+
+/// <summary>Platform-agnostic delivery order status before mapping to <see cref="OrderStatus"/>.</summary>
+public enum UnifiedDeliveryStatus
+{
+    Pending = 0,
+    Confirmed = 1,
+    Preparing = 2,
+    Ready = 3,
+    Delivered = 4,
+    Cancelled = 5
+}