Fix admin route access and backend configuration

- Added /admin redirect to login page in nginx config
- Fixed backend server.js route ordering for proper admin handling
- Updated authentication middleware and routes
- Added user management routes
- Configured PostgreSQL integration
- Updated environment configuration

Sky_Art_shop/Controllers/DiagnosticsController.cs

@@ -0,0 +1,36 @@
+using Microsoft.AspNetCore.Mvc;
+using SkyArtShop.Models;
+using SkyArtShop.Services;
+
+namespace SkyArtShop.Controllers
+{
+    [Route("diagnostics")]
+    public class DiagnosticsController : Controller
+    {
+        private readonly MongoDBService _mongoService;
+
+        public DiagnosticsController(MongoDBService mongoService)
+        {
+            _mongoService = mongoService;
+        }
+
+        [HttpGet("products")]
+        public async Task<IActionResult> Products()
+        {
+            var products = await _mongoService.GetAllAsync<Product>("Products");
+
+            var report = products.Select(p => new
+            {
+                p.Id,
+                p.Name,
+                p.ImageUrl,
+                ImagesCount = p.Images?.Count ?? 0,
+                FirstImage = p.Images?.FirstOrDefault(),
+                HasImageUrl = !string.IsNullOrEmpty(p.ImageUrl),
+                HasImages = p.Images != null && p.Images.Any()
+            }).ToList();
+
+            return Json(report);
+        }
+    }
+}