feat(ui): SMTP config form TlsMode field

Add a TlsMode read-only row and a None/StartTLS/SSL select to the SMTP
Configuration page edit form. New configs default to None; edits load
and persist the chosen mode through the repository.

src/ScadaLink.CentralUI/Components/Pages/Notifications/SmtpConfiguration.razor

@@ -50,6 +50,8 @@
                             <div class="col-md-8">@smtp.Host:@smtp.Port</div>
                             <div class="col-md-4 text-muted">Auth Type</div>
                             <div class="col-md-8"><span class="badge bg-secondary">@smtp.AuthType</span></div>
+                            <div class="col-md-4 text-muted">TLS Mode</div>
+                            <div class="col-md-8">@(string.IsNullOrWhiteSpace(smtp.TlsMode) ? "(not set)" : smtp.TlsMode)</div>
                             <div class="col-md-4 text-muted">From Address</div>
                             <div class="col-md-8">@smtp.FromAddress</div>
                             <div class="col-md-4 text-muted">Credentials</div>
@@ -73,13 +75,21 @@
                                 <label class="form-label">Port</label>
                                 <input type="number" class="form-control" @bind="_port" min="1" max="65535" />
                             </div>
-                            <div class="col-md-8">
+                            <div class="col-md-4">
                                 <label class="form-label">Auth Type</label>
                                 <select class="form-select" @bind="_authType">
                                     <option>OAuth2</option>
                                     <option>Basic</option>
                                 </select>
                             </div>
+                            <div class="col-md-4">
+                                <label class="form-label">TLS Mode</label>
+                                <select class="form-select" @bind="_tlsMode">
+                                    <option>None</option>
+                                    <option>StartTLS</option>
+                                    <option>SSL</option>
+                                </select>
+                            </div>
                             <div class="col-12">
                                 <label class="form-label">Credentials</label>
                                 <input type="password" class="form-control" @bind="_credentials"
@@ -122,6 +132,7 @@
     private string _host = string.Empty;
     private int _port = 587;
     private string _authType = "OAuth2";
+    private string? _tlsMode;
     private string? _credentials;
     private string _fromAddress = string.Empty;
     private string? _formError;
@@ -154,6 +165,7 @@
         _host = string.Empty;
         _port = 587;
         _authType = "OAuth2";
+        _tlsMode = "None";
         _credentials = null;
         _fromAddress = string.Empty;
         _formError = null;
@@ -166,6 +178,7 @@
         _host = smtp.Host;
         _port = smtp.Port;
         _authType = smtp.AuthType;
+        _tlsMode = smtp.TlsMode;
         _credentials = smtp.Credentials;
         _fromAddress = smtp.FromAddress;
         _formError = null;
@@ -194,6 +207,7 @@
                 _editingSmtp.Host = _host.Trim();
                 _editingSmtp.Port = _port;
                 _editingSmtp.AuthType = _authType;
+                _editingSmtp.TlsMode = _tlsMode;
                 _editingSmtp.Credentials = _credentials?.Trim();
                 _editingSmtp.FromAddress = _fromAddress.Trim();
                 await NotificationRepository.UpdateSmtpConfigurationAsync(_editingSmtp);
@@ -203,6 +217,7 @@
                 var smtp = new SmtpConfigurationEntity(_host.Trim(), _authType, _fromAddress.Trim())
                 {
                     Port = _port,
+                    TlsMode = _tlsMode,
                     Credentials = _credentials?.Trim()
                 };
                 await NotificationRepository.AddSmtpConfigurationAsync(smtp);

tests/ScadaLink.CentralUI.Tests/Pages/SmtpConfigurationPageTests.cs

@@ -0,0 +1,112 @@
+using System.Security.Claims;
+using Bunit;
+using Microsoft.AspNetCore.Components.Authorization;
+using Microsoft.Extensions.DependencyInjection;
+using NSubstitute;
+using ScadaLink.Commons.Entities.Notifications;
+using ScadaLink.Commons.Interfaces.Repositories;
+using SmtpConfigurationPage = ScadaLink.CentralUI.Components.Pages.Notifications.SmtpConfiguration;
+
+namespace ScadaLink.CentralUI.Tests.Pages;
+
+/// <summary>
+/// bUnit rendering tests for the SMTP Configuration page — specifically the TlsMode
+/// field added so the UI exposes all five user-relevant SmtpConfiguration fields.
+/// </summary>
+public class SmtpConfigurationPageTests : BunitContext
+{
+    private void WireAuth()
+    {
+        var claims = new[]
+        {
+            new Claim("Username", "tester"),
+            new Claim(ClaimTypes.Role, "Admin"),
+        };
+        var user = new ClaimsPrincipal(new ClaimsIdentity(claims, "TestAuth"));
+        Services.AddSingleton<AuthenticationStateProvider>(new TestAuthStateProvider(user));
+        Services.AddAuthorizationCore();
+    }
+
+    private static SmtpConfiguration Sample() =>
+        new("smtp.example.com", "Basic", "noreply@example.com")
+        {
+            Id = 1,
+            Port = 587,
+            TlsMode = "StartTLS",
+            Credentials = "user:pass",
+        };
+
+    [Fact]
+    public void EditForm_RendersTlsModeSelectWithAllThreeModes()
+    {
+        var repo = Substitute.For<INotificationRepository>();
+        repo.GetAllSmtpConfigurationsAsync()
+            .Returns(Task.FromResult<IReadOnlyList<SmtpConfiguration>>(
+                new List<SmtpConfiguration> { Sample() }));
+        Services.AddSingleton(repo);
+        WireAuth();
+
+        var cut = Render<SmtpConfigurationPage>();
+        cut.WaitForState(() => cut.Markup.Contains("smtp.example.com"));
+
+        cut.FindAll("button").First(b => b.TextContent.Contains("Edit")).Click();
+
+        cut.WaitForAssertion(() =>
+        {
+            var selects = cut.FindAll("select");
+            var tlsSelect = selects.Single(s => s.QuerySelectorAll("option")
+                .Any(o => o.TextContent == "StartTLS"));
+            var modes = tlsSelect.QuerySelectorAll("option").Select(o => o.TextContent).ToList();
+            Assert.Equal(new[] { "None", "StartTLS", "SSL" }, modes);
+        });
+    }
+
+    [Fact]
+    public void ReadOnlyView_ShowsTlsMode()
+    {
+        var repo = Substitute.For<INotificationRepository>();
+        repo.GetAllSmtpConfigurationsAsync()
+            .Returns(Task.FromResult<IReadOnlyList<SmtpConfiguration>>(
+                new List<SmtpConfiguration> { Sample() }));
+        Services.AddSingleton(repo);
+        WireAuth();
+
+        var cut = Render<SmtpConfigurationPage>();
+
+        cut.WaitForAssertion(() =>
+        {
+            Assert.Contains("TLS Mode", cut.Markup);
+            Assert.Contains("StartTLS", cut.Markup);
+        });
+    }
+
+    [Fact]
+    public void SavingEdit_PersistsChosenTlsMode()
+    {
+        var config = Sample();
+        var repo = Substitute.For<INotificationRepository>();
+        repo.GetAllSmtpConfigurationsAsync()
+            .Returns(Task.FromResult<IReadOnlyList<SmtpConfiguration>>(
+                new List<SmtpConfiguration> { config }));
+        Services.AddSingleton(repo);
+        WireAuth();
+
+        var cut = Render<SmtpConfigurationPage>();
+        cut.WaitForState(() => cut.Markup.Contains("smtp.example.com"));
+
+        cut.FindAll("button").First(b => b.TextContent.Contains("Edit")).Click();
+
+        var tlsSelect = cut.FindAll("select")
+            .Single(s => s.QuerySelectorAll("option").Any(o => o.TextContent == "StartTLS"));
+        tlsSelect.Change("SSL");
+
+        cut.FindAll("button").First(b => b.TextContent.Contains("Save")).Click();
+
+        cut.WaitForAssertion(() =>
+        {
+            repo.Received().UpdateSmtpConfigurationAsync(
+                Arg.Is<SmtpConfiguration>(c => c.TlsMode == "SSL"));
+            repo.Received().SaveChangesAsync();
+        });
+    }
+}