Whats new implementation.

Wino.Calendar.ViewModels/CalendarAppShellViewModel.cs

@@ -72,10 +72,14 @@ public partial class CalendarAppShellViewModel : CalendarBaseViewModel,
                              IAccountService accountService,
                              ICalendarService calendarService,
                              IAccountCalendarStateService accountCalendarStateService,
-                             INavigationService navigationService)
+                             INavigationService navigationService,
+                             IDialogServiceBase dialogService,
+                             IUpdateManager updateManager)
     {
         _accountService = accountService;
         _calendarService = calendarService;
+        _dialogService = dialogService;
+        _updateManager = updateManager;
 
         AccountCalendarStateService = accountCalendarStateService;
         AccountCalendarStateService.AccountCalendarSelectionStateChanged += UpdateAccountCalendarRequested;
@@ -123,9 +127,24 @@ public partial class CalendarAppShellViewModel : CalendarBaseViewModel,
 
         await InitializeAccountCalendarsAsync();
 
+        await ShowWhatIsNewIfNeededAsync();
+
         TodayClicked();
     }
 
+    private async Task ShowWhatIsNewIfNeededAsync()
+    {
+        if (!_updateManager.ShouldShowUpdateNotes())
+            return;
+
+        var notes = await _updateManager.GetLatestUpdateNotesAsync();
+
+        if (notes.Sections.Count == 0)
+            return;
+
+        await _dialogService.ShowWhatIsNewDialogAsync(notes);
+    }
+
     private async void AccountCalendarStateCollectivelyChanged(object sender, GroupedAccountCalendarViewModel e)
     {
         // When using three-state checkbox, multiple accounts will be selected/unselected at the same time.
@@ -271,6 +290,8 @@ public partial class CalendarAppShellViewModel : CalendarBaseViewModel,
     private DateTime? _navigationDate;
     private readonly IAccountService _accountService;
     private readonly ICalendarService _calendarService;
+    private readonly IDialogServiceBase _dialogService;
+    private readonly IUpdateManager _updateManager;
 
     #region Commands
 

Wino.Core.Domain/BasicTypesJsonContext.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Text.Json.Serialization;
+using Wino.Core.Domain.Models.Updates;
 
 namespace Wino.Core.Domain;
 
@@ -8,4 +9,6 @@ namespace Wino.Core.Domain;
 [JsonSerializable(typeof(int))]
 [JsonSerializable(typeof(List<string>))]
 [JsonSerializable(typeof(bool))]
+[JsonSerializable(typeof(UpdateNotes))]
+[JsonSerializable(typeof(List<UpdateNoteSection>))]
 public partial class BasicTypesJsonContext : JsonSerializerContext;

Wino.Core.Domain/Constants.cs

@@ -19,6 +19,7 @@ public static class Constants
     public const string ToastModeKey = nameof(ToastModeKey);
     public const string ToastModeMail = nameof(ToastModeMail);
     public const string ToastModeCalendar = nameof(ToastModeCalendar);
+    public const string ToastMigrationRequiredKey = nameof(ToastMigrationRequiredKey);
 
     public const string ClientLogFile = "Client_.log";
     public const string ServerLogFile = "Server_.log";

Wino.Core.Domain/Interfaces/IAppMigration.cs

@@ -0,0 +1,15 @@
+using System.Threading.Tasks;
+
+namespace Wino.Core.Domain.Interfaces;
+
+/// <summary>
+/// Represents a one-time app or data migration that runs when a user updates to a new version.
+/// </summary>
+public interface IAppMigration
+{
+    /// <summary>Gets the unique identifier for this migration, used to track completion in local settings.</summary>
+    string MigrationId { get; }
+
+    /// <summary>Executes the migration logic.</summary>
+    Task ExecuteAsync();
+}

Wino.Core.Domain/Interfaces/IDialogServiceBase.cs

@@ -5,6 +5,7 @@ using Wino.Core.Domain.Enums;
 using Wino.Core.Domain.Models.Accounts;
 using Wino.Core.Domain.Models.Common;
 using Wino.Core.Domain.Models.Printing;
+using Wino.Core.Domain.Models.Updates;
 
 namespace Wino.Core.Domain.Interfaces;
 
@@ -30,4 +31,10 @@ public interface IDialogServiceBase
     Task<List<SharedFile>> PickFilesAsync(params object[] typeFilters);
     Task<string> PickFilePathAsync(string saveFileName);
     Task<WebView2PrintSettingsModel> ShowPrintDialogAsync(WebView2PrintSettingsModel initialSettings = null);
+
+    /// <summary>
+    /// Presents the "What's New" dialog for the current version.
+    /// This dialog is undismissable and runs any pending migrations when the user clicks "Get Started".
+    /// </summary>
+    Task ShowWhatIsNewDialogAsync(UpdateNotes notes);
 }

Wino.Core.Domain/Interfaces/INotificationBuilder.cs

@@ -40,4 +40,10 @@ public interface INotificationBuilder
     /// Creates a calendar reminder toast for the specified calendar item.
     /// </summary>
     Task CreateCalendarReminderNotificationAsync(CalendarItem calendarItem, long reminderDurationInSeconds);
+
+    /// <summary>
+    /// Shows a notification that a migration is required for the new app version.
+    /// Synchronization is stopped and the user is prompted to open the app.
+    /// </summary>
+    void CreateMigrationRequiredNotification();
 }

Wino.Core.Domain/Interfaces/IUpdateManager.cs

@@ -0,0 +1,26 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Wino.Core.Domain.Models.Updates;
+
+namespace Wino.Core.Domain.Interfaces;
+
+public interface IUpdateManager
+{
+    /// <summary>Loads and parses the update notes for the current version from the bundled asset file.</summary>
+    Task<UpdateNotes> GetLatestUpdateNotesAsync();
+
+    /// <summary>Returns true if the current version's update notes have not yet been shown to the user.</summary>
+    bool ShouldShowUpdateNotes();
+
+    /// <summary>Stores a flag in local settings indicating the update notes for the current version have been seen.</summary>
+    void MarkUpdateNotesAsSeen();
+
+    /// <summary>Returns true if any registered migration has not yet been completed.</summary>
+    bool HasPendingMigrations();
+
+    /// <summary>Runs all pending migrations in order and marks each as completed in local settings.</summary>
+    Task RunPendingMigrationsAsync();
+
+    /// <summary>Registers migrations to be tracked and executed by this manager.</summary>
+    void RegisterMigrations(IEnumerable<IAppMigration> migrations);
+}

Wino.Core.Domain/Models/Updates/UpdateNoteSection.cs

@@ -0,0 +1,27 @@
+using System.Text.Json.Serialization;
+
+namespace Wino.Core.Domain.Models.Updates;
+
+public class UpdateNoteSection
+{
+    [JsonPropertyName("title")]
+    public string Title { get; set; } = string.Empty;
+
+    [JsonPropertyName("description")]
+    public string Description { get; set; } = string.Empty;
+
+    [JsonPropertyName("imageUrl")]
+    public string ImageUrl { get; set; } = string.Empty;
+
+    [JsonPropertyName("imageWidth")]
+    public double? ImageWidth { get; set; }
+
+    [JsonPropertyName("imageHeight")]
+    public double? ImageHeight { get; set; }
+
+    /// <summary>Gets the image width for binding, returning NaN for auto-sizing when not specified.</summary>
+    public double ActualImageWidth => ImageWidth ?? double.NaN;
+
+    /// <summary>Gets the image height for binding, returning NaN for auto-sizing when not specified.</summary>
+    public double ActualImageHeight => ImageHeight ?? double.NaN;
+}

Wino.Core.Domain/Models/Updates/UpdateNotes.cs

@@ -0,0 +1,13 @@
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
+namespace Wino.Core.Domain.Models.Updates;
+
+public class UpdateNotes
+{
+    [JsonPropertyName("hasMigrations")]
+    public bool HasMigrations { get; set; }
+
+    [JsonPropertyName("sections")]
+    public List<UpdateNoteSection> Sections { get; set; } = [];
+}

Wino.Core.Domain/Translations/en_US/resources.json

@@ -983,5 +983,8 @@
     "CalendarAccountSettings_DefaultShowAs": "Default Show As Status",
     "CalendarAccountSettings_DefaultShowAsDescription": "Default availability status for new events created with this account",
     "CalendarAccountSettings_PrimaryCalendar": "Primary Calendar",
-    "CalendarAccountSettings_PrimaryCalendarDescription": "Mark this calendar as the primary calendar for the account"
+    "CalendarAccountSettings_PrimaryCalendarDescription": "Mark this calendar as the primary calendar for the account",
+    "WhatIsNew_GetStartedButton": "Get Started",
+    "WhatIsNew_MigrationNotification_Title": "Wino Mail Updated",
+    "WhatIsNew_MigrationNotification_Message": "Open the app to complete the update and see what's new."
 }

Wino.Mail.ViewModels/MailAppShellViewModel.cs

@@ -78,6 +78,7 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
     private readonly IMailDialogService _dialogService;
     private readonly IMimeFileService _mimeFileService;
     private readonly IWebView2RuntimeValidatorService _webView2RuntimeValidatorService;
+    private readonly IUpdateManager _updateManager;
 
     private readonly INativeAppService _nativeAppService;
     private readonly IMailService _mailService;
@@ -100,7 +101,8 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
                              IStatePersistanceService statePersistanceService,
                              IConfigurationService configurationService,
                              IStartupBehaviorService startupBehaviorService,
-                             IWebView2RuntimeValidatorService webView2RuntimeValidatorService)
+                             IWebView2RuntimeValidatorService webView2RuntimeValidatorService,
+                             IUpdateManager updateManager)
     {
         StatePersistenceService = statePersistanceService;
 
@@ -121,6 +123,7 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
         _notificationBuilder = notificationBuilder;
         _winoRequestDelegator = winoRequestDelegator;
         _webView2RuntimeValidatorService = webView2RuntimeValidatorService;
+        _updateManager = updateManager;
     }
 
     protected override void OnDispatcherAssigned()
@@ -251,6 +254,7 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
             await ForceAllAccountSynchronizationsAsync();
         }
 
+        await ShowWhatIsNewIfNeededAsync();
         await MakeSureEnableStartupLaunchAsync();
     }
 
@@ -264,6 +268,19 @@ public partial class MailAppShellViewModel : MailBaseViewModel,
         }
     }
 
+    private async Task ShowWhatIsNewIfNeededAsync()
+    {
+        if (!_updateManager.ShouldShowUpdateNotes())
+            return;
+
+        var notes = await _updateManager.GetLatestUpdateNotesAsync();
+
+        if (notes.Sections.Count == 0)
+            return;
+
+        await _dialogService.ShowWhatIsNewDialogAsync(notes);
+    }
+
     private async Task MakeSureEnableStartupLaunchAsync()
     {
         if (!_configurationService.Get<bool>(IsActivateStartupLaunchAskedKey, false))

Wino.Mail.WinUI/App.xaml.cs

@@ -22,6 +22,7 @@ using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Calendar;
 using Wino.Core.Domain.Models.MailItem;
 using Wino.Core.Domain.Models.Synchronization;
+using Wino.Core.Domain.Models.Updates;
 using Wino.Mail.Services;
 using Wino.Mail.ViewModels;
 using Wino.Mail.WinUI.Activation;
@@ -153,9 +154,18 @@ public partial class App : WinoApplication,
         _preferencesService = Services.GetRequiredService<IPreferencesService>();
         _accountService = Services.GetRequiredService<IAccountService>();
 
+        // Check whether the new version requires a migration before starting sync.
+        var updateManager = Services.GetRequiredService<IUpdateManager>();
+        var updateNotes = await updateManager.GetLatestUpdateNotesAsync();
+        bool hasPendingMigration = updateNotes.HasMigrations && updateManager.HasPendingMigrations();
+
         _preferencesService.PreferenceChanged -= PreferencesServiceChanged;
         _preferencesService.PreferenceChanged += PreferencesServiceChanged;
-        RestartAutoSynchronizationLoop();
+
+        // Hold off sync loop when a migration is required in startup-task (tray-only) mode.
+        // In foreground mode the sync loop starts normally; the ViewModel dialog handles migrations before sync kicks in.
+        if (!hasPendingMigration || !IsStartupTaskLaunch())
+            RestartAutoSynchronizationLoop();
 
         // Check if launched from toast notification.
         if (IsNotificationActivation(out AppNotificationActivatedEventArgs toastArgs))
@@ -179,12 +189,21 @@ public partial class App : WinoApplication,
         // Otherwise, activate the window normally.
         if (isStartupTaskLaunch)
         {
-            LogActivation("Launched by startup task. Window created but hidden (system tray only).");
+            if (hasPendingMigration)
-            // Window is created but not activated. User can show it from system tray.
+            {
+                // Notify the user to open the app to complete the update before sync can resume.
+                Services.GetRequiredService<INotificationBuilder>().CreateMigrationRequiredNotification();
+                LogActivation("Migration required for new version. Sync skipped. User notified via toast.");
+            }
+            else
+            {
+                LogActivation("Launched by startup task. Window created but hidden (system tray only).");
+            }
         }
         else
         {
             // Normal launch - show and activate the window.
+            // The What's New dialog is shown from MailAppShellViewModel.OnNavigatedTo once XamlRoot is ready.
             MainWindow?.Activate();
             LogActivation("Window created and activated.");
         }
@@ -222,6 +241,13 @@ public partial class App : WinoApplication,
     {
         var toastArguments = ToastArguments.Parse(toastArgs.Argument);
 
+        // Check migration notification activation first.
+        if (toastArguments.Contains(Constants.ToastMigrationRequiredKey))
+        {
+            await HandleMigrationToastActivationAsync();
+            return;
+        }
+
         // Check calendar reminder toast activation first.
         if (toastArguments.TryGetValue(Constants.ToastCalendarActionKey, out string calendarAction) &&
             calendarAction == Constants.ToastCalendarNavigateAction &&
@@ -251,6 +277,29 @@ public partial class App : WinoApplication,
         }
     }
 
+    /// <summary>
+    /// Handles activation from the migration-required toast notification.
+    /// Opens the app so the shell ViewModel can show the What's New dialog and run migrations.
+    /// </summary>
+    private async Task HandleMigrationToastActivationAsync()
+    {
+        LogActivation("Handling migration toast activation.");
+
+        if (!IsAppRunning())
+        {
+            await CreateAndActivateWindow(null!);
+        }
+        else
+        {
+            EnsureMainWindowVisibleAndForeground();
+        }
+
+        // The MailAppShellViewModel.OnNavigatedTo will detect ShouldShowUpdateNotes() == true
+        // and display the What's New dialog (including running migrations) once the XamlRoot is ready.
+        // Restart sync in case it was blocked.
+        RestartAutoSynchronizationLoop();
+    }
+
     private async Task HandleCalendarToastNavigationAsync(Guid calendarItemId)
     {
         var calendarService = Services.GetRequiredService<ICalendarService>();

Wino.Mail.WinUI/Assets/UpdateNotes/vnext.json

@@ -0,0 +1,40 @@
+{
+    "hasMigrations": false,
+    "sections": [
+        {
+            "title": "# Wino Calendar is here!",
+            "description": "You can now create local or remote CalDAV-compatible calendars, manage recurring events, and respond to invitations — all from within Wino.",
+            "imageUrl": "ms-appx:///Assets/AboutPageTile.png",
+            "imageWidth": 128,
+            "imageHeight": 128
+        },
+        {
+            "title": "# S/MIME Signing & Encryption",
+            "description": "Wino now supports signing and encrypting your emails with personal certificates. Keep your communications secure and verifiable.",
+            "imageUrl": "ms-appx:///Assets/AboutPageTile.png",
+            "imageWidth": 128,
+            "imageHeight": 128
+        },
+        {
+            "title": "# Threaded Mail View",
+            "description": "Emails are now grouped by conversation, making it easier to follow long discussions without losing context.",
+            "imageUrl": "ms-appx:///Assets/AboutPageTile.png",
+            "imageWidth": 128,
+            "imageHeight": 128
+        },
+        {
+            "title": "# Smarter Notifications",
+            "description": "Act on your emails directly from toast notifications — mark as read, delete, or archive without opening the app.",
+            "imageUrl": "ms-appx:///Assets/AboutPageTile.png",
+            "imageWidth": 128,
+            "imageHeight": 128
+        },
+        {
+            "title": "# And much more...",
+            "description": "Folder management, swipe actions, keyboard shortcuts, a custom print dialog, and significant performance improvements are all included in this release.\n\nThank you for using Wino Mail!",
+            "imageUrl": "ms-appx:///Assets/AboutPageTile.png",
+            "imageWidth": 128,
+            "imageHeight": 128
+        }
+    ]
+}

Wino.Mail.WinUI/Dialogs/WhatIsNewDialog.xaml

@@ -0,0 +1,70 @@
+<ContentDialog
+    x:Class="Wino.Dialogs.WhatIsNewDialog"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    xmlns:domain="using:Wino.Core.Domain"
+    xmlns:controls="using:CommunityToolkit.WinUI.Controls"
+    xmlns:models="using:Wino.Core.Domain.Models.Updates"
+    HorizontalContentAlignment="Stretch"
+    VerticalContentAlignment="Stretch"
+    Style="{StaticResource WinoDialogStyle}"
+    mc:Ignorable="d">
+
+    <ContentDialog.Resources>
+        <x:Double x:Key="ContentDialogMinWidth">480</x:Double>
+        <x:Double x:Key="ContentDialogMaxWidth">560</x:Double>
+        <x:Double x:Key="ContentDialogMinHeight">480</x:Double>
+        <x:Double x:Key="ContentDialogMaxHeight">700</x:Double>
+    </ContentDialog.Resources>
+
+    <Grid RowSpacing="12">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="*" />
+            <RowDefinition Height="Auto" />
+            <RowDefinition Height="Auto" />
+        </Grid.RowDefinitions>
+
+        <FlipView
+            x:Name="UpdateFlipView"
+            ItemsSource="{x:Bind Sections, Mode=OneTime}"
+            SelectionChanged="OnFlipViewSelectionChanged">
+            <FlipView.ItemTemplate>
+                <DataTemplate x:DataType="models:UpdateNoteSection">
+                    <ScrollViewer VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Disabled">
+                        <StackPanel Spacing="16" Padding="12,8">
+                            <controls:MarkdownTextBlock
+                                Text="{x:Bind Title, Mode=OneTime}"
+                                HorizontalAlignment="Center" />
+                            <Image
+                                Source="{x:Bind ImageUrl, Mode=OneTime}"
+                                Width="{x:Bind ActualImageWidth, Mode=OneTime}"
+                                Height="{x:Bind ActualImageHeight, Mode=OneTime}"
+                                HorizontalAlignment="Center"
+                                Stretch="Uniform" />
+                            <controls:MarkdownTextBlock
+                                Text="{x:Bind Description, Mode=OneTime}"
+                                HorizontalAlignment="Stretch" />
+                        </StackPanel>
+                    </ScrollViewer>
+                </DataTemplate>
+            </FlipView.ItemTemplate>
+        </FlipView>
+
+        <PipsPager
+            x:Name="FlipViewPager"
+            Grid.Row="1"
+            HorizontalAlignment="Center"
+            SelectedPageIndex="0"
+            SelectedIndexChanged="OnPipsPagerSelectedIndexChanged" />
+
+        <Button
+            x:Name="GetStartedButton"
+            Grid.Row="2"
+            HorizontalAlignment="Right"
+            Content="{x:Bind domain:Translator.WhatIsNew_GetStartedButton}"
+            Visibility="Collapsed"
+            Click="OnGetStartedClicked" />
+    </Grid>
+</ContentDialog>

Wino.Mail.WinUI/Dialogs/WhatIsNewDialog.xaml.cs

@@ -0,0 +1,72 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Input;
+using Windows.System;
+using Wino.Core.Domain.Interfaces;
+using Wino.Core.Domain.Models.Updates;
+
+namespace Wino.Dialogs;
+
+public sealed partial class WhatIsNewDialog : ContentDialog
+{
+    private readonly IUpdateManager _updateManager;
+
+    public List<UpdateNoteSection> Sections { get; }
+
+    public WhatIsNewDialog(UpdateNotes notes, IUpdateManager updateManager)
+    {
+        InitializeComponent();
+
+        _updateManager = updateManager;
+        Sections = notes.Sections;
+
+        // Set the number of pages in the pip pager after sections are assigned.
+        FlipViewPager.NumberOfPages = Sections.Count;
+
+        // Show the Get Started button immediately when there is only one page.
+        if (Sections.Count <= 1)
+            GetStartedButton.Visibility = Visibility.Visible;
+    }
+
+    protected override void OnKeyDown(KeyRoutedEventArgs e)
+    {
+        // Block ESC key to prevent accidental dismissal.
+        if (e.Key == VirtualKey.Escape)
+        {
+            e.Handled = true;
+            return;
+        }
+
+        base.OnKeyDown(e);
+    }
+
+    private void OnFlipViewSelectionChanged(object sender, SelectionChangedEventArgs e)
+    {
+        int selectedIndex = UpdateFlipView.SelectedIndex;
+
+        // Keep pip pager in sync with the flip view.
+        FlipViewPager.SelectedPageIndex = selectedIndex;
+
+        // Show Get Started button only on the last page.
+        GetStartedButton.Visibility = selectedIndex == Sections.Count - 1
+            ? Visibility.Visible
+            : Visibility.Collapsed;
+    }
+
+    private void OnPipsPagerSelectedIndexChanged(PipsPager sender, PipsPagerSelectedIndexChangedEventArgs args)
+    {
+        UpdateFlipView.SelectedIndex = sender.SelectedPageIndex;
+    }
+
+    private async void OnGetStartedClicked(object sender, RoutedEventArgs e)
+    {
+        GetStartedButton.IsEnabled = false;
+
+        await _updateManager.RunPendingMigrationsAsync();
+        _updateManager.MarkUpdateNotesAsSeen();
+
+        Hide();
+    }
+}

Wino.Mail.WinUI/Services/DialogService.cs

@@ -27,9 +27,9 @@ public class DialogService : DialogServiceBase, IMailDialogService
 {
     public DialogService(INewThemeService themeService,
                          IConfigurationService configurationService,
-                         IApplicationResourceManager<ResourceDictionary> applicationResourceManager) : base(themeService, configurationService, applicationResourceManager)
+                         IApplicationResourceManager<ResourceDictionary> applicationResourceManager,
+                         IUpdateManager updateManager) : base(themeService, configurationService, applicationResourceManager, updateManager)
     {
-
     }
 
     public async Task<ICreateAccountAliasDialog> ShowCreateAccountAliasDialogAsync()

Wino.Mail.WinUI/Services/DialogServiceBase.cs

@@ -16,6 +16,7 @@ using Wino.Core.Domain.Interfaces;
 using Wino.Core.Domain.Models.Accounts;
 using Wino.Core.Domain.Models.Common;
 using Wino.Core.Domain.Models.Printing;
+using Wino.Core.Domain.Models.Updates;
 using Wino.Dialogs;
 using Wino.Mail.WinUI.Dialogs;
 using Wino.Mail.WinUI.Extensions;
@@ -30,14 +31,16 @@ public class DialogServiceBase : IDialogServiceBase
 
     protected INewThemeService ThemeService { get; }
     protected IConfigurationService ConfigurationService { get; }
+    protected IUpdateManager UpdateManager { get; }
 
     protected IApplicationResourceManager<ResourceDictionary> ApplicationResourceManager { get; }
 
-    public DialogServiceBase(INewThemeService themeService, IConfigurationService configurationService, IApplicationResourceManager<ResourceDictionary> applicationResourceManager)
+    public DialogServiceBase(INewThemeService themeService, IConfigurationService configurationService, IApplicationResourceManager<ResourceDictionary> applicationResourceManager, IUpdateManager updateManager)
     {
         ThemeService = themeService;
         ConfigurationService = configurationService;
         ApplicationResourceManager = applicationResourceManager;
+        UpdateManager = updateManager;
     }
 
     protected XamlRoot? GetXamlRoot()
@@ -355,4 +358,14 @@ public class DialogServiceBase : IDialogServiceBase
             return null!;
         }
     }
+
+    public async Task ShowWhatIsNewDialogAsync(UpdateNotes notes)
+    {
+        var dialog = new WhatIsNewDialog(notes, UpdateManager)
+        {
+            RequestedTheme = ThemeService.RootTheme.ToWindowsElementTheme()
+        };
+
+        await HandleDialogPresentationAsync(dialog);
+    }
 }

Wino.Mail.WinUI/Services/NotificationBuilder.cs

@@ -317,6 +317,20 @@ public class NotificationBuilder : INotificationBuilder
         return Task.CompletedTask;
     }
 
+    public void CreateMigrationRequiredNotification()
+    {
+        var builder = new ToastContentBuilder();
+        builder.SetToastScenario(ToastScenario.Default);
+
+        builder.AddText(Translator.WhatIsNew_MigrationNotification_Title);
+        builder.AddText(Translator.WhatIsNew_MigrationNotification_Message);
+
+        builder.AddArgument(Constants.ToastMigrationRequiredKey, bool.TrueString);
+        builder.AddArgument(Constants.ToastModeKey, Constants.ToastModeMail);
+
+        ShowToast(builder);
+    }
+
     private static void ShowToast(ToastContentBuilder builder, string? tag = null)
     {
         var toastNotification = new ToastNotification(builder.GetToastContent().GetXml());

Wino.Mail.WinUI/Wino.Mail.WinUI.csproj

@@ -142,6 +142,7 @@
     <Content Include="AppThemes\Snowflake.xaml" />
     <Content Include="AppThemes\TestTheme.xaml" />
     <Content Include="Assets\ReleaseNotes\vnext.md" />
+    <Content Include="Assets\UpdateNotes\vnext.json" />
     <Content Include="Assets\Wino_Icon.ico" />
     <Content Include="BackgroundImages\Acrylic.jpg" />
     <Content Include="BackgroundImages\Clouds.jpg" />

Wino.Services/ServicesContainerSetup.cs

@@ -29,5 +29,6 @@ public static class ServicesContainerSetup
         services.AddSingleton<IContactPictureFileService, ContactPictureFileService>();
 
         services.AddTransient<ICalDavClient, CalDavClient>();
+        services.AddSingleton<IUpdateManager, UpdateManager>();
     }
 }

Wino.Services/UpdateManager.cs

@@ -0,0 +1,88 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.Json;
+using System.Threading.Tasks;
+using Wino.Core.Domain;
+using Wino.Core.Domain.Interfaces;
+using Wino.Core.Domain.Models.Updates;
+
+namespace Wino.Services;
+
+public class UpdateManager : IUpdateManager
+{
+    private const string UpdateNotesResourcePath = "ms-appx:///Assets/UpdateNotes/vnext.json";
+    private const string UpdateNotesSeenKeyFormat = "UpdateNotes_{0}_Shown";
+    private const string MigrationCompletedKeyFormat = "Migration_{0}_Completed";
+
+    private readonly IFileService _fileService;
+    private readonly IConfigurationService _configurationService;
+    private readonly INativeAppService _nativeAppService;
+    private readonly List<IAppMigration> _migrations = [];
+
+    private string _versionSeenKey = string.Empty;
+
+    public UpdateManager(IFileService fileService,
+                         IConfigurationService configurationService,
+                         INativeAppService nativeAppService)
+    {
+        _fileService = fileService;
+        _configurationService = configurationService;
+        _nativeAppService = nativeAppService;
+    }
+
+    private string GetVersionSeenKey()
+    {
+        if (string.IsNullOrEmpty(_versionSeenKey))
+        {
+            var version = _nativeAppService.GetFullAppVersion();
+            var sanitized = version.Replace(".", "_");
+            _versionSeenKey = string.Format(UpdateNotesSeenKeyFormat, sanitized);
+        }
+
+        return _versionSeenKey;
+    }
+
+    public async Task<UpdateNotes> GetLatestUpdateNotesAsync()
+    {
+        try
+        {
+            var json = await _fileService.GetFileContentByApplicationUriAsync(UpdateNotesResourcePath);
+
+            if (string.IsNullOrEmpty(json))
+                return new UpdateNotes();
+
+            return JsonSerializer.Deserialize(json, BasicTypesJsonContext.Default.UpdateNotes) ?? new UpdateNotes();
+        }
+        catch (Exception)
+        {
+            return new UpdateNotes();
+        }
+    }
+
+    public bool ShouldShowUpdateNotes()
+        => !_configurationService.Get(GetVersionSeenKey(), false);
+
+    public void MarkUpdateNotesAsSeen()
+        => _configurationService.Set(GetVersionSeenKey(), true);
+
+    public bool HasPendingMigrations()
+        => _migrations.Any(m => !_configurationService.Get(string.Format(MigrationCompletedKeyFormat, m.MigrationId), false));
+
+    public async Task RunPendingMigrationsAsync()
+    {
+        foreach (var migration in _migrations)
+        {
+            var key = string.Format(MigrationCompletedKeyFormat, migration.MigrationId);
+
+            if (!_configurationService.Get(key, false))
+            {
+                await migration.ExecuteAsync();
+                _configurationService.Set(key, true);
+            }
+        }
+    }
+
+    public void RegisterMigrations(IEnumerable<IAppMigration> migrations)
+        => _migrations.AddRange(migrations);
+}