create user

radiuscontroller/Services/AdminAuthService.cs

@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Components.Server.ProtectedBrowserStorage;
 using Microsoft.EntityFrameworkCore;
 using radiuscontroller.Data;
+using radiuscontroller.Models;
 
 namespace radiuscontroller.Services;
 
@@ -39,6 +40,39 @@ public class AdminAuthService
         }
     }
 
+    public async Task<bool> HasAnyAdminAsync()
+    {
+        return await _db.AdminUsers.AnyAsync();
+    }
+
+    public async Task<bool> RegisterInitialAdminAsync(string username, string password)
+    {
+        if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(password))
+            return false;
+
+        // Ensure first-time setup is only allowed if no admin users exist
+        if (await _db.AdminUsers.AnyAsync())
+            return false;
+
+        string cleanUsername = username.Trim().ToLowerInvariant();
+        string hash = BCrypt.Net.BCrypt.HashPassword(password.Trim());
+
+        var admin = new AdminUser
+        {
+            Username = cleanUsername,
+            PasswordHash = hash,
+            CreatedAt = DateTime.UtcNow
+        };
+
+        _db.AdminUsers.Add(admin);
+        await _db.SaveChangesAsync();
+
+        CurrentAdminUsername = admin.Username;
+        await _sessionStorage.SetAsync(SessionKey, admin.Username);
+        NotifyStateChanged();
+        return true;
+    }
+
     public async Task<bool> LoginAsync(string username, string password)
     {
         if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(password))