Initial scaffolding: PS_Launcher v0.2

Client (C# / .NET 8 / WPF, MVVM via CommunityToolkit.Mvvm):
- PSLauncher.App: WPF UI dark theme (Epic-style sidebar + hero + big play button)
  with UpdateAvailableDialog rendering Markdown release notes via Markdig.Wpf.
- PSLauncher.Core: services for installation registry (scans Proserve v{X.Y.Z}/),
  process launcher, manifest fetch, SHA-256 integrity, HTTP download with
  progress, ZIP install via .tmp + atomic rename, update orchestrator.
- PSLauncher.Models: RemoteManifest, InstalledVersion, LocalConfig DTOs.

Server (PHP 8 for OVH mutualisé, deployed under www/PS_Launcher/):
- Front controller + routes /manifest and /releasenotes/{version}.
- Static signed-manifest workflow with tools/sign-manifest.php CLI to
  recompute SHA-256 and sizeBytes after each ZIP upload.
- .htaccess: HTTPS redirect, rewrite, security headers.
- config.example.php template; real config.php is gitignored.

Cohabiting versions: each release lives in its own Proserve v{version}/ folder
under installRoot. Old versions are never deleted automatically.

Roadmap: v0.3 = HTTP Range resume + Polly retry + state.json,
v0.4 = MySQL license + Ed25519 signatures + DPAPI, v0.5 = settings/UX polish.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/PSLauncher.App/App.xaml

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+<Application x:Class="PSLauncher.App.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             ShutdownMode="OnMainWindowClose">
+    <Application.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="Resources/Theme.xaml" />
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </Application.Resources>
+</Application>

src/PSLauncher.App/App.xaml.cs

@@ -0,0 +1,84 @@
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Windows;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using PSLauncher.App.ViewModels;
+using PSLauncher.App.Views;
+using PSLauncher.Core.Configuration;
+using PSLauncher.Core.Downloads;
+using PSLauncher.Core.Installations;
+using PSLauncher.Core.Integrity;
+using PSLauncher.Core.Manifests;
+using PSLauncher.Core.Process;
+using PSLauncher.Core.Updates;
+using PSLauncher.Models;
+
+namespace PSLauncher.App;
+
+public partial class App : Application
+{
+    private IHost? _host;
+
+    protected override void OnStartup(StartupEventArgs e)
+    {
+        base.OnStartup(e);
+
+        _host = Host.CreateDefaultBuilder()
+            .ConfigureLogging(b => { b.ClearProviders(); b.AddDebug(); })
+            .ConfigureServices((_, services) =>
+            {
+                services.AddSingleton<IConfigStore, ConfigStore>();
+                services.AddSingleton<LocalConfig>(sp => sp.GetRequiredService<IConfigStore>().Load());
+
+                // HttpClient partagé (timeout long pour les gros téléchargements)
+                services.AddSingleton(sp =>
+                {
+                    var http = new HttpClient(new SocketsHttpHandler
+                    {
+                        PooledConnectionLifetime = TimeSpan.FromMinutes(5),
+                        AutomaticDecompression = System.Net.DecompressionMethods.All
+                    })
+                    {
+                        Timeout = Timeout.InfiniteTimeSpan
+                    };
+                    http.DefaultRequestHeaders.UserAgent.Add(new ProductInfoHeaderValue("PSLauncher", "0.2"));
+                    return http;
+                });
+
+                services.AddSingleton<IInstallationRegistry>(sp =>
+                    new InstallationRegistry(
+                        sp.GetRequiredService<ILogger<InstallationRegistry>>(),
+                        () => sp.GetRequiredService<LocalConfig>().InstallRoot));
+
+                services.AddSingleton<IProcessLauncher, ProcessLauncher>();
+                services.AddSingleton<IIntegrityService, IntegrityService>();
+                services.AddSingleton<IZipInstaller, ZipInstaller>();
+
+                services.AddSingleton<IManifestService>(sp =>
+                    new ManifestService(
+                        sp.GetRequiredService<HttpClient>(),
+                        () => sp.GetRequiredService<LocalConfig>().ServerBaseUrl,
+                        sp.GetRequiredService<ILogger<ManifestService>>()));
+
+                services.AddSingleton<IDownloadManager, DownloadManager>();
+                services.AddSingleton<IUpdateChecker, UpdateChecker>();
+
+                services.AddSingleton<MainViewModel>();
+                services.AddSingleton<MainWindow>();
+            })
+            .Build();
+
+        var window = _host.Services.GetRequiredService<MainWindow>();
+        window.DataContext = _host.Services.GetRequiredService<MainViewModel>();
+        MainWindow = window;
+        window.Show();
+    }
+
+    protected override void OnExit(ExitEventArgs e)
+    {
+        _host?.Dispose();
+        base.OnExit(e);
+    }
+}

src/PSLauncher.App/PSLauncher.App.csproj

@@ -0,0 +1,37 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net8.0-windows</TargetFramework>
+    <UseWPF>true</UseWPF>
+    <Nullable>enable</Nullable>
+    <LangVersion>latest</LangVersion>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <ApplicationIcon></ApplicationIcon>
+    <AssemblyName>PSLauncher</AssemblyName>
+    <RootNamespace>PSLauncher.App</RootNamespace>
+
+    <!-- Single-file self-contained publish profile (used by `dotnet publish`) -->
+    <PublishSingleFile>true</PublishSingleFile>
+    <SelfContained>true</SelfContained>
+    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
+    <IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>
+    <EnableCompressionInSingleFile>true</EnableCompressionInSingleFile>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="CommunityToolkit.Mvvm" Version="8.3.2" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.1" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.1" />
+    <PackageReference Include="Microsoft.Extensions.Logging" Version="8.0.1" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="8.0.1" />
+    <PackageReference Include="Markdig" Version="0.37.0" />
+    <PackageReference Include="Markdig.Wpf" Version="0.5.0.1" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\PSLauncher.Core\PSLauncher.Core.csproj" />
+    <ProjectReference Include="..\PSLauncher.Models\PSLauncher.Models.csproj" />
+  </ItemGroup>
+
+</Project>

src/PSLauncher.App/Resources/Theme.xaml

@@ -0,0 +1,103 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+
+    <BooleanToVisibilityConverter x:Key="BoolToVisibility" />
+
+    <!-- Epic Games inspired dark palette -->
+    <SolidColorBrush x:Key="Brush.Bg.Window"   Color="#1B1B1F" />
+    <SolidColorBrush x:Key="Brush.Bg.Sidebar"  Color="#202024" />
+    <SolidColorBrush x:Key="Brush.Bg.Card"     Color="#26262B" />
+    <SolidColorBrush x:Key="Brush.Bg.Footer"   Color="#0F0F12" />
+    <SolidColorBrush x:Key="Brush.Border"      Color="#37373D" />
+    <SolidColorBrush x:Key="Brush.Text.Primary"   Color="#F2F2F2" />
+    <SolidColorBrush x:Key="Brush.Text.Secondary" Color="#A0A0A8" />
+    <SolidColorBrush x:Key="Brush.Accent"      Color="#0078D4" />
+    <SolidColorBrush x:Key="Brush.AccentHover" Color="#1A8CE0" />
+    <SolidColorBrush x:Key="Brush.Play"        Color="#0CA84B" />
+    <SolidColorBrush x:Key="Brush.PlayHover"   Color="#10C257" />
+
+    <Style TargetType="Window">
+        <Setter Property="Background" Value="{StaticResource Brush.Bg.Window}" />
+        <Setter Property="Foreground" Value="{StaticResource Brush.Text.Primary}" />
+        <Setter Property="FontFamily" Value="Segoe UI" />
+        <Setter Property="FontSize" Value="13" />
+    </Style>
+
+    <Style TargetType="TextBlock">
+        <Setter Property="Foreground" Value="{StaticResource Brush.Text.Primary}" />
+    </Style>
+
+    <Style x:Key="SidebarItem" TargetType="RadioButton">
+        <Setter Property="Foreground" Value="{StaticResource Brush.Text.Secondary}" />
+        <Setter Property="Background" Value="Transparent" />
+        <Setter Property="Cursor" Value="Hand" />
+        <Setter Property="FontSize" Value="14" />
+        <Setter Property="HorizontalContentAlignment" Value="Left" />
+        <Setter Property="Padding" Value="20,10" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="RadioButton">
+                    <Border x:Name="Bd"
+                            Background="{TemplateBinding Background}"
+                            Padding="{TemplateBinding Padding}">
+                        <ContentPresenter VerticalAlignment="Center" />
+                    </Border>
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsMouseOver" Value="True">
+                            <Setter TargetName="Bd" Property="Background" Value="#2C2C32" />
+                        </Trigger>
+                        <Trigger Property="IsChecked" Value="True">
+                            <Setter TargetName="Bd" Property="Background" Value="#2C2C32" />
+                            <Setter Property="Foreground" Value="{StaticResource Brush.Text.Primary}" />
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <Style x:Key="PrimaryButton" TargetType="Button">
+        <Setter Property="Background" Value="{StaticResource Brush.Play}" />
+        <Setter Property="Foreground" Value="White" />
+        <Setter Property="FontSize" Value="18" />
+        <Setter Property="FontWeight" Value="SemiBold" />
+        <Setter Property="Padding" Value="48,14" />
+        <Setter Property="BorderThickness" Value="0" />
+        <Setter Property="Cursor" Value="Hand" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="Button">
+                    <Border x:Name="Bd"
+                            Background="{TemplateBinding Background}"
+                            CornerRadius="4"
+                            Padding="{TemplateBinding Padding}">
+                        <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
+                    </Border>
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsMouseOver" Value="True">
+                            <Setter TargetName="Bd" Property="Background" Value="{StaticResource Brush.PlayHover}" />
+                        </Trigger>
+                        <Trigger Property="IsEnabled" Value="False">
+                            <Setter TargetName="Bd" Property="Background" Value="#444" />
+                            <Setter Property="Foreground" Value="#888" />
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <Style x:Key="SecondaryButton" TargetType="Button" BasedOn="{StaticResource PrimaryButton}">
+        <Setter Property="Background" Value="#3A3A40" />
+        <Setter Property="FontSize" Value="13" />
+        <Setter Property="FontWeight" Value="Normal" />
+        <Setter Property="Padding" Value="14,8" />
+    </Style>
+
+    <Style x:Key="VersionPill" TargetType="Border">
+        <Setter Property="Background" Value="#2C2C32" />
+        <Setter Property="CornerRadius" Value="12" />
+        <Setter Property="Padding" Value="10,4" />
+    </Style>
+
+</ResourceDictionary>

src/PSLauncher.App/ViewModels/InstalledVersionViewModel.cs

@@ -0,0 +1,27 @@
+using PSLauncher.Models;
+
+namespace PSLauncher.App.ViewModels;
+
+public sealed class InstalledVersionViewModel
+{
+    public InstalledVersion Model { get; }
+
+    public InstalledVersionViewModel(InstalledVersion model) => Model = model;
+
+    public string Display => $"v{Model.Version}";
+
+    public string Subtitle =>
+        $"{FormatSize(Model.SizeBytes)} • Installée le {Model.InstalledAt.ToLocalTime():dd/MM/yyyy}";
+
+    private static string FormatSize(long bytes)
+    {
+        if (bytes <= 0) return "—";
+        string[] units = { "o", "Ko", "Mo", "Go", "To" };
+        double v = bytes;
+        int u = 0;
+        while (v >= 1024 && u < units.Length - 1) { v /= 1024; u++; }
+        return $"{v:0.#} {units[u]}";
+    }
+
+    public override string ToString() => Display;
+}

src/PSLauncher.App/ViewModels/MainViewModel.cs

@@ -0,0 +1,359 @@
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using System.IO;
+using System.Windows;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using Microsoft.Extensions.Logging;
+using PSLauncher.App.Views;
+using PSLauncher.Core.Configuration;
+using PSLauncher.Core.Downloads;
+using PSLauncher.Core.Installations;
+using PSLauncher.Core.Manifests;
+using PSLauncher.Core.Process;
+using PSLauncher.Core.Updates;
+using PSLauncher.Models;
+
+namespace PSLauncher.App.ViewModels;
+
+public sealed partial class MainViewModel : ObservableObject
+{
+    private readonly IInstallationRegistry _registry;
+    private readonly IProcessLauncher _processLauncher;
+    private readonly IConfigStore _configStore;
+    private readonly LocalConfig _config;
+    private readonly IManifestService _manifestService;
+    private readonly IUpdateChecker _updateChecker;
+    private readonly IDownloadManager _downloadManager;
+    private readonly IZipInstaller _zipInstaller;
+    private readonly ILogger<MainViewModel> _logger;
+
+    private CancellationTokenSource? _downloadCts;
+
+    public ObservableCollection<InstalledVersionViewModel> InstalledVersions { get; } = new();
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(StatusBadge))]
+    [NotifyPropertyChangedFor(nameof(PrimaryActionLabel))]
+    [NotifyPropertyChangedFor(nameof(PrimaryActionEnabled))]
+    [NotifyPropertyChangedFor(nameof(HeroTitle))]
+    [NotifyCanExecuteChangedFor(nameof(PrimaryActionCommand))]
+    private InstalledVersionViewModel? _selectedVersion;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(StatusBadge))]
+    [NotifyPropertyChangedFor(nameof(PrimaryActionLabel))]
+    [NotifyPropertyChangedFor(nameof(PrimaryActionEnabled))]
+    private VersionManifest? _availableUpdate;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(FooterText))]
+    [NotifyPropertyChangedFor(nameof(FooterVisibility))]
+    private string? _statusMessage;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(FooterText))]
+    [NotifyPropertyChangedFor(nameof(FooterVisibility))]
+    [NotifyPropertyChangedFor(nameof(StatusBadge))]
+    [NotifyPropertyChangedFor(nameof(PrimaryActionLabel))]
+    [NotifyPropertyChangedFor(nameof(PrimaryActionEnabled))]
+    [NotifyCanExecuteChangedFor(nameof(PrimaryActionCommand))]
+    [NotifyCanExecuteChangedFor(nameof(CheckForUpdatesCommand))]
+    private bool _isBusy;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(FooterText))]
+    [NotifyPropertyChangedFor(nameof(FooterVisibility))]
+    private double _progressPercent;
+
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(FooterText))]
+    private string? _progressDetail;
+
+    public string StatusBadge
+    {
+        get
+        {
+            if (IsBusy) return "● En cours";
+            if (AvailableUpdate is not null) return "🔔 MAJ disponible";
+            if (SelectedVersion is null) return "Aucune version";
+            return "● Installée";
+        }
+    }
+
+    public string PrimaryActionLabel
+    {
+        get
+        {
+            if (IsBusy) return "Veuillez patienter…";
+            if (AvailableUpdate is not null && SelectedVersion is null)
+                return $"⬇  INSTALLER v{AvailableUpdate.Version}";
+            if (AvailableUpdate is not null)
+                return $"⬇  TÉLÉCHARGER v{AvailableUpdate.Version}";
+            return SelectedVersion is null ? "Aucune version disponible" : "▶  LANCER";
+        }
+    }
+
+    public bool PrimaryActionEnabled => !IsBusy && (SelectedVersion is not null || AvailableUpdate is not null);
+
+    public string HeroTitle
+    {
+        get
+        {
+            if (AvailableUpdate is not null) return $"PROSERVE — v{AvailableUpdate.Version}";
+            return SelectedVersion is null ? "PROSERVE" : $"PROSERVE — {SelectedVersion.Display}";
+        }
+    }
+
+    public string LicenseSummary => "License : non configurée (v0.4)";
+
+    public string EmptyHint =>
+        $"Aucune version trouvée dans :\n{_config.InstallRoot}\n\n" +
+        "Configure l'URL serveur dans config.json puis clique « Vérifier les mises à jour », " +
+        "ou place un dossier « Proserve v{X.Y.Z} » contenant PROSERVE_UE_5_5.exe à cet emplacement.";
+
+    public Visibility EmptyHintVisibility => InstalledVersions.Count == 0 ? Visibility.Visible : Visibility.Collapsed;
+
+    public Visibility FooterVisibility => IsBusy || !string.IsNullOrEmpty(StatusMessage) ? Visibility.Visible : Visibility.Collapsed;
+
+    public string FooterText
+    {
+        get
+        {
+            if (!string.IsNullOrEmpty(ProgressDetail)) return ProgressDetail;
+            return StatusMessage ?? string.Empty;
+        }
+    }
+
+    public MainViewModel(
+        IInstallationRegistry registry,
+        IProcessLauncher processLauncher,
+        IConfigStore configStore,
+        LocalConfig config,
+        IManifestService manifestService,
+        IUpdateChecker updateChecker,
+        IDownloadManager downloadManager,
+        IZipInstaller zipInstaller,
+        ILogger<MainViewModel> logger)
+    {
+        _registry = registry;
+        _processLauncher = processLauncher;
+        _configStore = configStore;
+        _config = config;
+        _manifestService = manifestService;
+        _updateChecker = updateChecker;
+        _downloadManager = downloadManager;
+        _zipInstaller = zipInstaller;
+        _logger = logger;
+        Refresh();
+    }
+
+    [RelayCommand]
+    private void Refresh()
+    {
+        InstalledVersions.Clear();
+        foreach (var v in _registry.Scan())
+            InstalledVersions.Add(new InstalledVersionViewModel(v));
+
+        SelectedVersion = !string.IsNullOrEmpty(_config.LastLaunchedVersion)
+            ? InstalledVersions.FirstOrDefault(v => v.Model.Version == _config.LastLaunchedVersion)
+              ?? InstalledVersions.FirstOrDefault()
+            : InstalledVersions.FirstOrDefault();
+
+        OnPropertyChanged(nameof(EmptyHint));
+        OnPropertyChanged(nameof(EmptyHintVisibility));
+    }
+
+    [RelayCommand(CanExecute = nameof(CanCheckUpdates))]
+    private async Task CheckForUpdatesAsync()
+    {
+        IsBusy = true;
+        StatusMessage = "Vérification des mises à jour…";
+        try
+        {
+            var result = await _updateChecker.CheckAsync(CancellationToken.None);
+            if (result.Error is not null)
+            {
+                StatusMessage = $"Erreur : {result.Error}";
+                AvailableUpdate = null;
+                return;
+            }
+
+            if (result.IsLatestNewerThanInstalled && result.LatestRemote is not null)
+            {
+                AvailableUpdate = result.LatestRemote;
+                StatusMessage = $"Nouvelle version disponible : v{result.LatestRemote.Version}";
+            }
+            else
+            {
+                AvailableUpdate = null;
+                StatusMessage = result.LatestRemote is not null
+                    ? $"À jour (v{result.LatestRemote.Version})"
+                    : "Aucune version distante trouvée";
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Update check failed");
+            StatusMessage = $"Erreur : {ex.Message}";
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
+    private bool CanCheckUpdates() => !IsBusy;
+
+    [RelayCommand(CanExecute = nameof(PrimaryActionEnabled))]
+    private async Task PrimaryActionAsync()
+    {
+        if (AvailableUpdate is not null)
+        {
+            await DownloadAndInstallAsync(AvailableUpdate);
+            return;
+        }
+
+        if (SelectedVersion is null) return;
+        try
+        {
+            _processLauncher.Launch(SelectedVersion.Model);
+            _config.LastLaunchedVersion = SelectedVersion.Model.Version;
+            _configStore.Save(_config);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Failed to launch");
+            MessageBox.Show(
+                $"Impossible de lancer la version :\n\n{ex.Message}",
+                "Erreur de lancement",
+                MessageBoxButton.OK, MessageBoxImage.Error);
+        }
+    }
+
+    private async Task DownloadAndInstallAsync(VersionManifest version)
+    {
+        // 1) Récupère release notes et propose dialog
+        string notes;
+        try
+        {
+            notes = !string.IsNullOrEmpty(version.ReleaseNotesUrl)
+                ? await _manifestService.FetchReleaseNotesAsync(version.ReleaseNotesUrl, CancellationToken.None)
+                : "_Aucune release note fournie._";
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Failed to fetch release notes");
+            notes = "_Release notes indisponibles._";
+        }
+
+        var dialog = new UpdateAvailableDialog(version, notes)
+        {
+            Owner = Application.Current.MainWindow
+        };
+        dialog.ShowDialog();
+        if (!dialog.DownloadRequested) return;
+
+        IsBusy = true;
+        _downloadCts = new CancellationTokenSource();
+        try
+        {
+            var url = new Uri(version.Download.Url);
+            var job = new DownloadJob(version.Version, url, version.Download.SizeBytes, version.Download.Sha256);
+
+            var progress = new Progress<DownloadProgress>(p => UpdateDlProgress(version.Version, p));
+            StatusMessage = $"Téléchargement v{version.Version}…";
+            var zipPath = await _downloadManager.DownloadAsync(job, progress, _downloadCts.Token);
+
+            // 2) Extraction
+            StatusMessage = $"Installation v{version.Version}…";
+            var folderName = version.GetInstallFolderName();
+            var target = Path.Combine(_config.InstallRoot, folderName);
+            var installProgress = new Progress<InstallProgress>(ip =>
+            {
+                if (ip.BytesTotal <= 0) return;
+                ProgressPercent = (double)ip.BytesDone / ip.BytesTotal * 100.0;
+                ProgressDetail = $"Extraction : {ip.EntriesDone}/{ip.EntriesTotal} fichiers ({FormatSize(ip.BytesDone)} / {FormatSize(ip.BytesTotal)})";
+            });
+            await _zipInstaller.InstallAsync(zipPath, target, installProgress, _downloadCts.Token);
+
+            // 3) Nettoyage du ZIP téléchargé (le user peut le rétablir depuis le serveur s'il en a besoin)
+            try { File.Delete(zipPath); } catch { /* non critique */ }
+
+            StatusMessage = $"v{version.Version} installée avec succès";
+            ProgressDetail = null;
+            ProgressPercent = 0;
+            AvailableUpdate = null;
+            Refresh();
+        }
+        catch (OperationCanceledException)
+        {
+            StatusMessage = "Téléchargement annulé";
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Download/install failed");
+            MessageBox.Show(
+                $"Le téléchargement ou l'installation a échoué :\n\n{ex.Message}",
+                "Erreur",
+                MessageBoxButton.OK, MessageBoxImage.Error);
+            StatusMessage = $"Erreur : {ex.Message}";
+        }
+        finally
+        {
+            _downloadCts?.Dispose();
+            _downloadCts = null;
+            IsBusy = false;
+        }
+    }
+
+    private void UpdateDlProgress(string version, DownloadProgress p)
+    {
+        if (p.TotalBytes > 0)
+            ProgressPercent = (double)p.BytesDownloaded / p.TotalBytes * 100.0;
+
+        var sb = new System.Text.StringBuilder();
+        sb.Append("⬇ v").Append(version).Append(" : ");
+        sb.Append(FormatSize(p.BytesDownloaded));
+        if (p.TotalBytes > 0) sb.Append(" / ").Append(FormatSize(p.TotalBytes));
+        if (p.BytesPerSecond > 0) sb.Append(" • ").Append(FormatSize((long)p.BytesPerSecond)).Append("/s");
+        if (p.Eta is { } eta && eta.TotalSeconds > 1) sb.Append(" • ETA ").Append(FormatEta(eta));
+        ProgressDetail = sb.ToString();
+    }
+
+    [RelayCommand]
+    private void OpenFolder()
+    {
+        var path = SelectedVersion?.Model.FolderPath ?? _config.InstallRoot;
+        if (string.IsNullOrEmpty(path) || !Directory.Exists(path)) return;
+        Process.Start(new ProcessStartInfo
+        {
+            FileName = path,
+            UseShellExecute = true,
+            Verb = "open"
+        });
+    }
+
+    [RelayCommand]
+    private void CancelDownload()
+    {
+        _downloadCts?.Cancel();
+    }
+
+    private static string FormatSize(long bytes)
+    {
+        if (bytes <= 0) return "0 o";
+        string[] units = { "o", "Ko", "Mo", "Go", "To" };
+        double v = bytes;
+        int u = 0;
+        while (v >= 1024 && u < units.Length - 1) { v /= 1024; u++; }
+        return $"{v:0.#} {units[u]}";
+    }
+
+    private static string FormatEta(TimeSpan eta)
+    {
+        if (eta.TotalHours >= 1) return $"{(int)eta.TotalHours}h{eta.Minutes:D2}";
+        if (eta.TotalMinutes >= 1) return $"{(int)eta.TotalMinutes}m{eta.Seconds:D2}";
+        return $"{(int)eta.TotalSeconds}s";
+    }
+}

src/PSLauncher.App/Views/MainWindow.xaml

@@ -0,0 +1,194 @@
+<Window x:Class="PSLauncher.App.Views.MainWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:PSLauncher.App.ViewModels"
+        xmlns:views="clr-namespace:PSLauncher.App.Views"
+        Title="PROSERVE Launcher"
+        Width="1280" Height="800"
+        MinWidth="900" MinHeight="600"
+        WindowStartupLocation="CenterScreen"
+        d:DataContext="{d:DesignInstance Type=vm:MainViewModel}"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        mc:Ignorable="d"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006">
+
+    <Grid>
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto" />   <!-- Top bar -->
+            <RowDefinition Height="*" />      <!-- Body -->
+            <RowDefinition Height="Auto" />   <!-- Footer (download) -->
+        </Grid.RowDefinitions>
+
+        <!-- Top bar -->
+        <Border Grid.Row="0" Background="{StaticResource Brush.Bg.Sidebar}"
+                BorderBrush="{StaticResource Brush.Border}" BorderThickness="0,0,0,1"
+                Padding="20,12">
+            <Grid>
+                <TextBlock Text="PROSERVE" FontSize="18" FontWeight="Bold"
+                           Foreground="{StaticResource Brush.Text.Primary}"
+                           VerticalAlignment="Center" />
+                <StackPanel HorizontalAlignment="Right" Orientation="Horizontal" VerticalAlignment="Center">
+                    <TextBlock Text="{Binding LicenseSummary}"
+                               Foreground="{StaticResource Brush.Text.Secondary}"
+                               VerticalAlignment="Center" Margin="0,0,12,0" />
+                </StackPanel>
+            </Grid>
+        </Border>
+
+        <!-- Body : sidebar + content -->
+        <Grid Grid.Row="1">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="200" />
+                <ColumnDefinition Width="*" />
+            </Grid.ColumnDefinitions>
+
+            <!-- Sidebar -->
+            <Border Grid.Column="0" Background="{StaticResource Brush.Bg.Sidebar}"
+                    BorderBrush="{StaticResource Brush.Border}" BorderThickness="0,0,1,0">
+                <StackPanel>
+                    <RadioButton Style="{StaticResource SidebarItem}" GroupName="Nav"
+                                 Content="📚  Bibliothèque" IsChecked="True" />
+                    <RadioButton Style="{StaticResource SidebarItem}" GroupName="Nav"
+                                 Content="📰  Nouveautés" IsEnabled="False" />
+                    <RadioButton Style="{StaticResource SidebarItem}" GroupName="Nav"
+                                 Content="⚙️  Paramètres" IsEnabled="False" />
+                </StackPanel>
+            </Border>
+
+            <!-- Library content -->
+            <ScrollViewer Grid.Column="1" VerticalScrollBarVisibility="Auto">
+                <StackPanel Margin="40,30">
+
+                    <!-- Hero -->
+                    <Border Background="#2A2A30" CornerRadius="8" Height="280"
+                            BorderBrush="{StaticResource Brush.Border}" BorderThickness="1">
+                        <Grid>
+                            <TextBlock Text="PROSERVE"
+                                       FontSize="64" FontWeight="Bold"
+                                       Foreground="#3D3D45"
+                                       HorizontalAlignment="Center" VerticalAlignment="Center" />
+                            <Border VerticalAlignment="Bottom" HorizontalAlignment="Left"
+                                    Margin="24" Background="#000000B0"
+                                    CornerRadius="4" Padding="12,6">
+                                <TextBlock Text="{Binding HeroTitle}"
+                                           FontSize="22" FontWeight="SemiBold"
+                                           Foreground="White" />
+                            </Border>
+                        </Grid>
+                    </Border>
+
+                    <!-- Action row -->
+                    <Grid Margin="0,24,0,0">
+                        <Grid.ColumnDefinitions>
+                            <ColumnDefinition Width="Auto" />
+                            <ColumnDefinition Width="*" />
+                            <ColumnDefinition Width="Auto" />
+                        </Grid.ColumnDefinitions>
+
+                        <!-- Version selector -->
+                        <StackPanel Grid.Column="0" Orientation="Horizontal" VerticalAlignment="Center">
+                            <TextBlock Text="Version :" Foreground="{StaticResource Brush.Text.Secondary}"
+                                       VerticalAlignment="Center" Margin="0,0,10,0" />
+                            <ComboBox Width="160"
+                                      ItemsSource="{Binding InstalledVersions}"
+                                      DisplayMemberPath="Display"
+                                      SelectedItem="{Binding SelectedVersion, Mode=TwoWay}" />
+                            <Border Style="{StaticResource VersionPill}" Margin="12,0,0,0">
+                                <TextBlock Text="{Binding StatusBadge}" FontSize="12"
+                                           Foreground="{StaticResource Brush.Text.Primary}" />
+                            </Border>
+                        </StackPanel>
+
+                        <!-- Primary action -->
+                        <Button Grid.Column="2"
+                                Style="{StaticResource PrimaryButton}"
+                                Content="{Binding PrimaryActionLabel}"
+                                Command="{Binding PrimaryActionCommand}"
+                                IsEnabled="{Binding PrimaryActionEnabled}" />
+                    </Grid>
+
+                    <!-- Secondary actions -->
+                    <StackPanel Orientation="Horizontal" Margin="0,16,0,0">
+                        <Button Style="{StaticResource SecondaryButton}"
+                                Content="🔄  Vérifier les mises à jour"
+                                Command="{Binding CheckForUpdatesCommand}"
+                                Margin="0,0,10,0" />
+                        <Button Style="{StaticResource SecondaryButton}"
+                                Content="📁  Ouvrir le dossier"
+                                Command="{Binding OpenFolderCommand}"
+                                Margin="0,0,10,0" />
+                        <Button Style="{StaticResource SecondaryButton}"
+                                Content="🔍  Rescanner local"
+                                Command="{Binding RefreshCommand}" />
+                    </StackPanel>
+
+                    <!-- Installed versions list -->
+                    <TextBlock Text="Versions installées" FontSize="16" FontWeight="SemiBold"
+                               Margin="0,30,0,12"
+                               Foreground="{StaticResource Brush.Text.Primary}" />
+                    <ItemsControl ItemsSource="{Binding InstalledVersions}">
+                        <ItemsControl.ItemTemplate>
+                            <DataTemplate>
+                                <Border Background="{StaticResource Brush.Bg.Card}"
+                                        CornerRadius="6" Margin="0,0,0,8" Padding="16,12"
+                                        BorderBrush="{StaticResource Brush.Border}" BorderThickness="1">
+                                    <Grid>
+                                        <Grid.ColumnDefinitions>
+                                            <ColumnDefinition Width="*" />
+                                            <ColumnDefinition Width="Auto" />
+                                        </Grid.ColumnDefinitions>
+                                        <StackPanel Grid.Column="0">
+                                            <TextBlock Text="{Binding Display}"
+                                                       FontSize="15" FontWeight="SemiBold" />
+                                            <TextBlock Text="{Binding Subtitle}"
+                                                       FontSize="12"
+                                                       Foreground="{StaticResource Brush.Text.Secondary}"
+                                                       Margin="0,2,0,0" />
+                                        </StackPanel>
+                                    </Grid>
+                                </Border>
+                            </DataTemplate>
+                        </ItemsControl.ItemTemplate>
+                    </ItemsControl>
+
+                    <!-- Empty state -->
+                    <TextBlock Text="{Binding EmptyHint}"
+                               Foreground="{StaticResource Brush.Text.Secondary}"
+                               TextWrapping="Wrap" Margin="0,12,0,0"
+                               Visibility="{Binding EmptyHintVisibility}" />
+
+                </StackPanel>
+            </ScrollViewer>
+        </Grid>
+
+        <!-- Footer (download/install status) -->
+        <Border Grid.Row="2" Background="{StaticResource Brush.Bg.Footer}"
+                BorderBrush="{StaticResource Brush.Border}" BorderThickness="0,1,0,0"
+                Padding="20,8"
+                Visibility="{Binding FooterVisibility}">
+            <Grid>
+                <Grid.ColumnDefinitions>
+                    <ColumnDefinition Width="*" />
+                    <ColumnDefinition Width="Auto" />
+                </Grid.ColumnDefinitions>
+                <StackPanel Grid.Column="0">
+                    <TextBlock Text="{Binding FooterText}"
+                               Foreground="{StaticResource Brush.Text.Secondary}" />
+                    <ProgressBar Height="4" Margin="0,4,0,0"
+                                 Value="{Binding ProgressPercent}"
+                                 Maximum="100"
+                                 Foreground="{StaticResource Brush.Accent}"
+                                 Background="#2A2A30"
+                                 BorderThickness="0" />
+                </StackPanel>
+                <Button Grid.Column="1"
+                        Style="{StaticResource SecondaryButton}"
+                        Content="Annuler"
+                        VerticalAlignment="Center"
+                        Margin="12,0,0,0"
+                        Command="{Binding CancelDownloadCommand}"
+                        Visibility="{Binding IsBusy, Converter={StaticResource BoolToVisibility}}" />
+            </Grid>
+        </Border>
+    </Grid>
+</Window>

src/PSLauncher.App/Views/MainWindow.xaml.cs

@@ -0,0 +1,11 @@
+using System.Windows;
+
+namespace PSLauncher.App.Views;
+
+public partial class MainWindow : Window
+{
+    public MainWindow()
+    {
+        InitializeComponent();
+    }
+}

src/PSLauncher.App/Views/UpdateAvailableDialog.xaml

@@ -0,0 +1,50 @@
+<Window x:Class="PSLauncher.App.Views.UpdateAvailableDialog"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        Title="Mise à jour disponible"
+        Width="640" Height="540"
+        MinWidth="480" MinHeight="400"
+        WindowStartupLocation="CenterOwner"
+        Background="{StaticResource Brush.Bg.Window}">
+    <Grid Margin="24">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto" />
+            <RowDefinition Height="Auto" />
+            <RowDefinition Height="*" />
+            <RowDefinition Height="Auto" />
+        </Grid.RowDefinitions>
+
+        <TextBlock Grid.Row="0"
+                   Text="{Binding Title}"
+                   FontSize="22" FontWeight="SemiBold"
+                   Foreground="{StaticResource Brush.Text.Primary}" />
+
+        <TextBlock Grid.Row="1"
+                   Text="{Binding Subtitle}"
+                   Foreground="{StaticResource Brush.Text.Secondary}"
+                   Margin="0,4,0,18" />
+
+        <Border Grid.Row="2"
+                Background="{StaticResource Brush.Bg.Card}"
+                BorderBrush="{StaticResource Brush.Border}" BorderThickness="1"
+                CornerRadius="6"
+                Padding="16">
+            <FlowDocumentScrollViewer
+                Document="{Binding ReleaseNotesDocument}"
+                Foreground="{StaticResource Brush.Text.Primary}"
+                Background="Transparent" />
+        </Border>
+
+        <StackPanel Grid.Row="3" Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,18,0,0">
+            <Button Style="{StaticResource SecondaryButton}"
+                    Content="Plus tard"
+                    IsCancel="True"
+                    Margin="0,0,12,0"
+                    Click="OnLater" />
+            <Button Style="{StaticResource PrimaryButton}"
+                    Content="⬇  Télécharger"
+                    Padding="32,10"
+                    Click="OnDownload" />
+        </StackPanel>
+    </Grid>
+</Window>

src/PSLauncher.App/Views/UpdateAvailableDialog.xaml.cs

@@ -0,0 +1,61 @@
+using System.Windows;
+using System.Windows.Documents;
+using Markdig;
+using Markdig.Wpf;
+using PSLauncher.Models;
+
+namespace PSLauncher.App.Views;
+
+public partial class UpdateAvailableDialog : Window
+{
+    public UpdateAvailableDialog(VersionManifest version, string releaseNotesMarkdown)
+    {
+        InitializeComponent();
+
+        var pipeline = new MarkdownPipelineBuilder()
+            .UseSupportedExtensions()
+            .Build();
+        FlowDocument doc;
+        try
+        {
+            doc = Markdig.Wpf.Markdown.ToFlowDocument(releaseNotesMarkdown, pipeline);
+        }
+        catch
+        {
+            doc = new FlowDocument(new Paragraph(new Run(releaseNotesMarkdown)));
+        }
+
+        DataContext = new
+        {
+            Title = $"Proserve v{version.Version} disponible",
+            Subtitle = $"Date de release : {version.ReleasedAt.ToLocalTime():dd MMMM yyyy} • {FormatSize(version.Download.SizeBytes)}",
+            ReleaseNotesDocument = doc
+        };
+    }
+
+    public bool DownloadRequested { get; private set; }
+
+    private void OnDownload(object sender, RoutedEventArgs e)
+    {
+        DownloadRequested = true;
+        DialogResult = true;
+        Close();
+    }
+
+    private void OnLater(object sender, RoutedEventArgs e)
+    {
+        DownloadRequested = false;
+        DialogResult = false;
+        Close();
+    }
+
+    private static string FormatSize(long bytes)
+    {
+        if (bytes <= 0) return "taille inconnue";
+        string[] units = { "o", "Ko", "Mo", "Go", "To" };
+        double v = bytes;
+        int u = 0;
+        while (v >= 1024 && u < units.Length - 1) { v /= 1024; u++; }
+        return $"{v:0.#} {units[u]}";
+    }
+}