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/Views/Shared/Components/FooterPages/Default.cshtml

@@ -0,0 +1,11 @@
+@model List<SkyArtShop.Models.Page>
+
+@if (Model != null && Model.Any())
+{
+    <ul>
+        @foreach (var p in Model)
+        {
+            <li><a href="/page/@p.PageSlug">@p.PageName</a></li>
+        }
+    </ul>
+}