Enhance documentation with new features: added dark/light/system theme support, instructions page, and application catalog. Updated API and domain model for app management and automatic migrations on startup. Improved frontend structure with new routes and features for user instructions and app management.

backend/src/PnvPanel.Infrastructure/Identity/CurrentUser.cs

@@ -0,0 +1,23 @@
+using System.Security.Claims;
+using Microsoft.AspNetCore.Http;
+using PnvPanel.Application.Common.Interfaces;
+
+namespace PnvPanel.Infrastructure.Identity;
+
+internal sealed class CurrentUser(IHttpContextAccessor httpContextAccessor) : ICurrentUser
+{
+    private ClaimsPrincipal? Principal => httpContextAccessor.HttpContext?.User;
+
+    public Guid? UserId
+    {
+        get
+        {
+            var value = Principal?.FindFirstValue(ClaimTypes.NameIdentifier);
+            return Guid.TryParse(value, out var id) ? id : null;
+        }
+    }
+
+    public string? UserName => Principal?.FindFirstValue(ClaimTypes.Name);
+
+    public bool IsAuthenticated => Principal?.Identity?.IsAuthenticated ?? false;
+}