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.Admin.API/Services/IAdminWebsiteService.cs

@@ -0,0 +1,20 @@
+using Meezi.Admin.API.Controllers;
+
+namespace Meezi.Admin.API.Services;
+
+public interface IAdminWebsiteService
+{
+    Task<object> ListPostsAsync(int page, int limit, bool? published, CancellationToken ct);
+    Task<object?> GetPostAsync(string id, CancellationToken ct);
+    Task<object> CreatePostAsync(UpsertPostRequest req, CancellationToken ct);
+    Task<object?> UpdatePostAsync(string id, UpsertPostRequest req, CancellationToken ct);
+    Task DeletePostAsync(string id, CancellationToken ct);
+    Task SetPublishedAsync(string id, bool published, CancellationToken ct);
+
+    Task<object> ListCommentsAsync(bool? approved, int page, int limit, CancellationToken ct);
+    Task SetCommentApprovedAsync(string id, bool approved, CancellationToken ct);
+    Task DeleteCommentAsync(string id, CancellationToken ct);
+
+    Task<object> ListDemoRequestsAsync(string? status, int page, int limit, CancellationToken ct);
+    Task UpdateDemoStatusAsync(string id, string status, string? adminNotes, CancellationToken ct);
+}