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.Infrastructure/Data/Migrations/20260522211634_OrderDisplayNumber.cs

@@ -0,0 +1,52 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Meezi.Infrastructure.Data.Migrations
+{
+    /// <inheritdoc />
+    public partial class OrderDisplayNumber : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<int>(
+                name: "DisplayNumber",
+                table: "Orders",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.Sql(
+                """
+                WITH numbered AS (
+                    SELECT "Id",
+                           ROW_NUMBER() OVER (PARTITION BY "CafeId" ORDER BY "CreatedAt", "Id") AS rn
+                    FROM "Orders"
+                )
+                UPDATE "Orders" o
+                SET "DisplayNumber" = n.rn
+                FROM numbered n
+                WHERE o."Id" = n."Id";
+                """);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Orders_CafeId_DisplayNumber",
+                table: "Orders",
+                columns: new[] { "CafeId", "DisplayNumber" },
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex(
+                name: "IX_Orders_CafeId_DisplayNumber",
+                table: "Orders");
+
+            migrationBuilder.DropColumn(
+                name: "DisplayNumber",
+                table: "Orders");
+        }
+    }
+}