feat(client): migrate Login.razor to IAuthApiClient

- Replace IAuthService injection with IAuthApiClient
- Keep ICryptoService for credential encryption
- Add AuthStateProvider injection to notify authentication state
- Use result.Switch() pattern for ApiResult<LoginResultModel> handling
- Properly handle ValidationError with FieldErrors dictionary

NEW/src/JdeScoping.Client/Pages/Login.razor

@@ -1,6 +1,9 @@
 @page "/login"
 @using JdeScoping.Core.Models.Auth
-@inject IAuthService AuthService
+@using JdeScoping.Core.ApiContracts
+@inject IAuthApiClient AuthApi
+@inject ICryptoService CryptoService
+@inject AuthStateProvider AuthStateProvider
 @inject NavigationManager NavigationManager
 
 <PageTitle>Login - JDE Scoping Tool</PageTitle>
@@ -60,17 +63,47 @@
 
         try
         {
-            var result = await AuthService.LoginAsync(_loginModel);
+            // Encrypt credentials
+            var encryptedData = await CryptoService.EncryptLoginAsync(_loginModel);
+            var request = new EncryptedLoginRequest(encryptedData);
 
-            if (result.Success)
-            {
-                var returnUrl = string.IsNullOrEmpty(ReturnUrl) ? "/" : ReturnUrl;
-                NavigationManager.NavigateTo(returnUrl);
-            }
-            else
-            {
-                _errorMessage = result.ErrorMessage ?? "Login failed. Please check your credentials.";
-            }
+            var result = await AuthApi.LoginAsync(request);
+            result.Switch(
+                loginResult =>
+                {
+                    if (loginResult.Success && loginResult.User is not null)
+                    {
+                        // Notify auth state provider of successful login
+                        var userViewModel = new JdeScoping.Client.Models.UserInfoViewModel
+                        {
+                            Username = loginResult.User.Username,
+                            FirstName = loginResult.User.FirstName,
+                            LastName = loginResult.User.LastName,
+                            DisplayName = loginResult.User.DisplayName,
+                            EmailAddress = loginResult.User.EmailAddress,
+                            Title = loginResult.User.Title
+                        };
+                        _ = AuthStateProvider.MarkUserAsAuthenticated(userViewModel);
+
+                        var returnUrl = string.IsNullOrEmpty(ReturnUrl) ? "/" : ReturnUrl;
+                        NavigationManager.NavigateTo(returnUrl);
+                    }
+                    else
+                    {
+                        _errorMessage = loginResult.ErrorMessage ?? "Login failed. Please check your credentials.";
+                    }
+                },
+                notFound => { _errorMessage = "Authentication service not found."; },
+                validation =>
+                {
+                    // ValidationError has FieldErrors dictionary, not Message property
+                    var errors = validation.FieldErrors.SelectMany(e => e.Value);
+                    _errorMessage = string.Join(", ", errors);
+                },
+                unauthorized => { _errorMessage = "Invalid credentials."; },
+                forbidden => { _errorMessage = "Access denied."; },
+                error => { _errorMessage = error.Message; }
+            );
         }
         catch (Exception ex)
         {