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.API/Configuration/DeliveryPlatformsOptions.cs

@@ -0,0 +1,34 @@
+namespace Meezi.API.Configuration;
+
+public class DeliveryPlatformsOptions
+{
+    public const string SectionName = "DeliveryPlatforms";
+
+    public SnappfoodPlatformOptions Snappfood { get; set; } = new();
+    public Tap30PlatformOptions Tap30 { get; set; } = new();
+    public DigikalaPlatformOptions Digikala { get; set; } = new();
+
+    public decimal DefaultSnappfoodCommissionPercent { get; set; } = 18m;
+    public decimal DefaultTap30CommissionPercent { get; set; } = 15m;
+    public decimal DefaultDigikalaCommissionPercent { get; set; } = 12m;
+}
+
+public class SnappfoodPlatformOptions
+{
+    public string WebhookSecret { get; set; } = "";
+    public string ApiKey { get; set; } = "";
+    public string ApiBaseUrl { get; set; } = "";
+}
+
+public class Tap30PlatformOptions
+{
+    public string WebhookSecret { get; set; } = "";
+    public string ApiKey { get; set; } = "";
+    public string ApiBaseUrl { get; set; } = "";
+}
+
+public class DigikalaPlatformOptions
+{
+    public string WebhookSecret { get; set; } = "";
+    public bool Enabled { get; set; }
+}

src/Meezi.API/Configuration/MenuAi3dOptions.cs

@@ -0,0 +1,14 @@
+namespace Meezi.API.Configuration;
+
+public class MenuAi3dOptions
+{
+    public const string SectionName = "Ai3d";
+
+    public string ApiKey { get; set; } = "";
+    public string BaseUrl { get; set; } = "https://api.meshy.ai";
+    public string ImageTo3dPath { get; set; } = "/openapi/v1/image-to-3d";
+    public int PollIntervalSeconds { get; set; } = 4;
+    public int PollTimeoutSeconds { get; set; } = 300;
+    /// <summary>When true and ApiKey is empty, returns a minimal GLB (development only).</summary>
+    public bool AllowDevStub { get; set; }
+}