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.Core/Process/ProcessLauncher.cs

@@ -0,0 +1,44 @@
+using System.Diagnostics;
+using Microsoft.Extensions.Logging;
+using PSLauncher.Models;
+using SysProcess = System.Diagnostics.Process;
+
+namespace PSLauncher.Core.Process;
+
+public sealed class ProcessLauncher : IProcessLauncher
+{
+    private readonly ILogger<ProcessLauncher> _logger;
+
+    public ProcessLauncher(ILogger<ProcessLauncher> logger) => _logger = logger;
+
+    public SysProcess Launch(InstalledVersion version, string[]? args = null)
+    {
+        if (!File.Exists(version.ExecutablePath))
+            throw new FileNotFoundException("Executable not found", version.ExecutablePath);
+
+        var psi = new ProcessStartInfo
+        {
+            FileName = version.ExecutablePath,
+            WorkingDirectory = version.FolderPath,
+            UseShellExecute = true
+        };
+        if (args is not null)
+        {
+            foreach (var arg in args) psi.ArgumentList.Add(arg);
+        }
+
+        _logger.LogInformation("Launching {Exe}", version.ExecutablePath);
+        return SysProcess.Start(psi)
+               ?? throw new InvalidOperationException("Process.Start returned null");
+    }
+
+    public bool IsRunning(InstalledVersion version)
+    {
+        var name = Path.GetFileNameWithoutExtension(version.ExecutablePath);
+        return SysProcess.GetProcessesByName(name).Any(p =>
+        {
+            try { return string.Equals(p.MainModule?.FileName, version.ExecutablePath, StringComparison.OrdinalIgnoreCase); }
+            catch { return false; }
+        });
+    }
+}