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

Controllers/DiagnosticsController.cs

@@ -0,0 +1,34 @@
+using System.Linq;
+using System.Threading.Tasks;
+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 data = (await _mongoService.GetAllAsync<Product>("Products")).Select((Product p) => new
+		{
+			Id = p.Id,
+			Name = p.Name,
+			ImageUrl = 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(data);
+	}
+}