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>

server/api/routes/Releasenotes.php

@@ -0,0 +1,24 @@
+<?php
+declare(strict_types=1);
+
+namespace PSLauncher\Routes;
+
+use PSLauncher\Response;
+
+final class Releasenotes
+{
+    public static function handle(string $version): void
+    {
+        if (!preg_match('/^[0-9]+\.[0-9]+\.[0-9]+$/', $version)) {
+            Response::error('invalid_version', 'Bad version format', 400);
+        }
+        $file = dirname(__DIR__, 2) . "/releasenotes/{$version}.md";
+        if (!is_file($file)) {
+            Response::error('not_found', "Release notes for {$version} not found", 404);
+        }
+        header('Cache-Control: public, max-age=3600, must-revalidate');
+        header('Content-Type: text/markdown; charset=utf-8');
+        header('Content-Length: ' . filesize($file));
+        readfile($file);
+    }
+}