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

Services/SqlDataService.cs

@@ -0,0 +1,98 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using SkyArtShop.Data;
+using SkyArtShop.Models;
+
+namespace SkyArtShop.Services;
+
+public class SqlDataService
+{
+	private readonly SkyArtShopDbContext _context;
+
+	public SqlDataService(SkyArtShopDbContext context)
+	{
+		_context = context;
+	}
+
+	public async Task<List<T>> GetAllAsync<T>() where T : class
+	{
+		return await _context.Set<T>().ToListAsync();
+	}
+
+	public async Task<T?> GetByIdAsync<T>(string id) where T : class
+	{
+		return await _context.Set<T>().FindAsync(id);
+	}
+
+	public async Task<T> InsertAsync<T>(T entity) where T : class
+	{
+		_context.Set<T>().Add(entity);
+		await _context.SaveChangesAsync();
+		return entity;
+	}
+
+	public async Task<T> UpdateAsync<T>(T entity) where T : class
+	{
+		_context.Set<T>().Update(entity);
+		await _context.SaveChangesAsync();
+		return entity;
+	}
+
+	public async Task DeleteAsync<T>(string id) where T : class
+	{
+		T val = await GetByIdAsync<T>(id);
+		if (val != null)
+		{
+			_context.Set<T>().Remove(val);
+			await _context.SaveChangesAsync();
+		}
+	}
+
+	public async Task<AdminUser?> GetUserByEmailAsync(string email)
+	{
+		return await _context.AdminUsers.FirstOrDefaultAsync((AdminUser u) => u.Email.ToLower() == email.ToLower());
+	}
+
+	public async Task<List<Product>> GetFeaturedProductsAsync()
+	{
+		return await _context.Products.Where((Product p) => p.IsFeatured && p.IsActive).ToListAsync();
+	}
+
+	public async Task<List<Product>> GetTopSellersAsync(int count = 10)
+	{
+		return await (from p in _context.Products
+			where p.IsTopSeller && p.IsActive
+			orderby p.UnitsSold descending
+			select p).Take(count).ToListAsync();
+	}
+
+	public async Task<Product?> GetProductBySlugAsync(string slug)
+	{
+		return await _context.Products.FirstOrDefaultAsync((Product p) => p.Slug == slug && p.IsActive);
+	}
+
+	public async Task<BlogPost?> GetBlogPostBySlugAsync(string slug)
+	{
+		return await _context.BlogPosts.FirstOrDefaultAsync((BlogPost b) => b.Slug == slug && b.IsPublished);
+	}
+
+	public async Task<Page?> GetPageBySlugAsync(string slug)
+	{
+		return await _context.Pages.FirstOrDefaultAsync((Page p) => p.PageSlug == slug && p.IsActive);
+	}
+
+	public async Task<SiteSettings?> GetSiteSettingsAsync()
+	{
+		return await _context.SiteSettings.FirstOrDefaultAsync();
+	}
+
+	public async Task<List<MenuItem>> GetActiveMenuItemsAsync()
+	{
+		return await (from m in _context.MenuItems
+			where m.IsActive
+			orderby m.DisplayOrder
+			select m).ToListAsync();
+	}
+}