Assembly-scanned services, options validator marker, UI tweaks, and config fixes

- Register ISettingsModalService, INotificationService, IUpdateCheckService via assembly scanning (marker interfaces)
- Add IApplicationOptionsValidator<TOptions> marker; scan only those for IValidateOptions registration
- Fix ApplicationLifecycleLoggingHostedService: log RestartCommand/ReloadCommand/StatusCommand (no ApplyCommand)
- NavMenu: spin animation for update-check button icon when checking; single icon with conditional nav-footer-spin class
- Add NotificationHost/NotificationToast components and NotificationService for toasts
- Effective config save flow, restore result, save service; various EffectiveConfig and DnsmasqOptions/validator updates
- Test and script updates; docker-compose.test.yml, appsettings, DnsmasqConfKeys/tooltips/sections

src/DnsmasqWebUI/Components/EffectiveConfig/Modals/EffectiveConfigSaveFlow.razor

@@ -2,13 +2,36 @@
 @using DnsmasqWebUI.Models.Dnsmasq
 @using DnsmasqWebUI.Models.Dnsmasq.EffectiveConfig
 @using DnsmasqWebUI.Infrastructure.Services.EffectiveConfig.Abstractions
+@using DnsmasqWebUI.Infrastructure.Services.UI.Notifications.Abstractions
+@inject IEffectiveConfigSaveService SaveService
+@inject INotificationService NotificationService
 
 @if (ShowModal)
 {
-    <EffectiveConfigSaveModal PendingChanges="@PendingChanges" Status="@Status" Session="@Session" OnClose="@OnClose" OnSave="@HandleSave" OnReverted="@HandleReverted" />
+    <EffectiveConfigSaveModal
+        PendingChanges="@PendingChanges"
+        Status="@Status"
+        Session="@Session"
+        SaveState="@_saveState"
+        SaveResult="@_saveResult"
+        RestoreResult="@_restoreResult"
+        OnClose="@OnClose"
+        OnSave="@HandleSave"
+        OnRestore="@HandleRestore"
+        OnReverted="@HandleReverted" />
 }
 
 @code {
+    public enum SaveUiState
+    {
+        Review,
+        Saving,
+        WriteFailed,
+        ReloadFailed,
+        RestoreInProgress,
+        RestoreFailed
+    }
+
     [Parameter] public bool ShowModal { get; set; }
     [Parameter] public IReadOnlyList<PendingEffectiveConfigChange> PendingChanges { get; set; } = null!;
     [Parameter] public DnsmasqServiceStatus? Status { get; set; }
@@ -16,6 +39,20 @@
     [Parameter] public EventCallback OnSaveCompleted { get; set; }
     [Parameter] public IEffectiveConfigEditSession Session { get; set; } = null!;
 
+    private SaveUiState _saveState = SaveUiState.Review;
+    private EffectiveConfigSaveResult? _saveResult;
+    private EffectiveConfigRestoreResult? _restoreResult;
+
+    protected override void OnParametersSet()
+    {
+        if (!ShowModal)
+        {
+            _saveState = SaveUiState.Review;
+            _saveResult = null;
+            _restoreResult = null;
+        }
+    }
+
     private async Task HandleReverted()
     {
         await InvokeAsync(StateHasChanged);
@@ -24,15 +61,60 @@
     private async Task HandleSave()
     {
         if (Session.PendingChanges.Count == 0) return;
-        try
+
+        _saveState = SaveUiState.Saving;
+        _saveResult = null;
+        _restoreResult = null;
+        await InvokeAsync(StateHasChanged);
+
+        var result = await Session.ApplyAsync();
+
+        _saveResult = result;
+        if (result.Saved && result.Reloaded)
         {
-            await Session.ApplyAsync();
+            var message = result.UserMessage ?? "Config saved and dnsmasq reloaded.";
+            NotificationService.ShowSuccess(message);
+            _saveState = SaveUiState.Review;
+            _saveResult = null;
             await OnClose.InvokeAsync();
             await OnSaveCompleted.InvokeAsync();
+            return;
         }
-        catch (Exception)
+
+        if (result.Saved && !result.Reloaded)
+            _saveState = SaveUiState.ReloadFailed;
+        else if (!result.Saved)
+            _saveState = SaveUiState.WriteFailed;
+        else
+            _saveState = SaveUiState.Review;
+
+        await InvokeAsync(StateHasChanged);
+    }
+
+    private async Task HandleRestore(string backupPath)
+    {
+        if (string.IsNullOrEmpty(backupPath)) return;
+
+        _saveState = SaveUiState.RestoreInProgress;
+        _restoreResult = null;
+        await InvokeAsync(StateHasChanged);
+
+        var result = await SaveService.RestoreAsync(backupPath);
+
+        _restoreResult = result;
+        if (result.Restored && result.Reloaded)
         {
-            // TODO: show error to user (e.g. toast or modal message)
+            var message = result.UserMessage ?? "Backup restored and dnsmasq reloaded.";
+            NotificationService.ShowSuccess(message);
+            _saveState = SaveUiState.Review;
+            _saveResult = null;
+            _restoreResult = null;
+            await OnClose.InvokeAsync();
+            await OnSaveCompleted.InvokeAsync();
+            return;
         }
+
+        _saveState = SaveUiState.RestoreFailed;
+        await InvokeAsync(StateHasChanged);
     }
 }