Settings: Database section with connection params, test, and replay button

New « BASE DE DONNÉES (XAMPP / MySQL) » section in Paramètres covering:

- Host / Port / User / Password / Database — defaults match a fresh XAMPP
  install (localhost:3306, root, empty password, "proserve"). Password is
  DPAPI-encrypted in config.json (same scheme as the license key).
- « Tester » button — opens a fresh MySqlConnection and runs SELECT 1.
  Shows ✓ OK or the connection error inline.
- « Appliquer automatiquement les migrations à l'install » checkbox — opt-in
  for the post-install migration step. Default true.
- « 🔁 Rejouer les migrations » button — manually re-runs ApplyMigrationsAsync
  on the latest installed version. Useful when the post-install run failed
  (XAMPP was off) or after a dev added a new SQL file. Live status « 3/5 :
  0042_add_index.sql » + final « ✓ N applied, M skipped » or « ✗ failure ».
- Hint paragraph below explaining the _migrations/ convention.

SettingsViewModel
- Pulls IDatabaseMigrationService and IInstallationRegistry via DI.
- Save() now also persists the DB block, encrypting the password before write.
- TestDbAsync temporarily swaps the in-memory config so the service sees the
  values being typed (without persisting until Save).

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

src/PSLauncher.Core/Localization/Strings.cs

@@ -138,6 +138,27 @@ public static class Strings
     public static string SettingsInstallation => T("INSTALLATION", "INSTALLATION",   "安装",          "การติดตั้ง",     "التثبيت");
     public static string SettingsCache      => T("CACHE DE TÉLÉCHARGEMENTS", "DOWNLOAD CACHE", "下载缓存", "แคชดาวน์โหลด", "ذاكرة التخزين المؤقت للتنزيلات");
     public static string SettingsLogs       => T("LOGS & APPLICATION", "LOGS & APP",  "日志与应用",     "บันทึกและแอป", "السجلات والتطبيق");
+    public static string SettingsDatabase   => T("BASE DE DONNÉES (XAMPP / MySQL)", "DATABASE (XAMPP / MySQL)", "数据库（XAMPP / MySQL）", "ฐานข้อมูล (XAMPP / MySQL)", "قاعدة البيانات (XAMPP / MySQL)");
+    public static string SettingsDbHost     => T("Hôte",                "Host",                "主机",          "โฮสต์",            "المضيف");
+    public static string SettingsDbPort     => T("Port",                "Port",                "端口",          "พอร์ต",           "المنفذ");
+    public static string SettingsDbUser     => T("Utilisateur",         "User",                "用户",          "ผู้ใช้",           "المستخدم");
+    public static string SettingsDbPassword => T("Mot de passe",        "Password",            "密码",          "รหัสผ่าน",         "كلمة المرور");
+    public static string SettingsDbName     => T("Nom de la base",      "Database name",       "数据库名称",     "ชื่อฐานข้อมูล",     "اسم قاعدة البيانات");
+    public static string SettingsDbAutoMigrate => T(
+        "Appliquer automatiquement les migrations à l'install d'une nouvelle version",
+        "Automatically apply migrations when installing a new version",
+        "安装新版本时自动应用迁移",
+        "ปรับใช้การโยกย้ายโดยอัตโนมัติเมื่อติดตั้งเวอร์ชันใหม่",
+        "تطبيق الترقيات تلقائياً عند تثبيت نسخة جديدة"
+    );
+    public static string SettingsDbReplay   => T("🔁  Rejouer les migrations", "🔁  Replay migrations", "🔁  重新执行迁移", "🔁  เรียกใช้การโยกย้ายอีกครั้ง", "🔁  إعادة تشغيل الترقيات");
+    public static string SettingsDbHint     => T(
+        "Le launcher applique automatiquement les scripts SQL bundled dans _migrations/ de chaque ZIP PROSERVE. Mot de passe stocké chiffré DPAPI.",
+        "The launcher automatically applies SQL scripts bundled in each PROSERVE ZIP's _migrations/ folder. Password stored DPAPI-encrypted.",
+        "启动器自动应用每个 PROSERVE ZIP 的 _migrations/ 文件夹中捆绑的 SQL 脚本。密码使用 DPAPI 加密存储。",
+        "Launcher จะปรับใช้สคริปต์ SQL ที่บรรจุใน _migrations/ ของ ZIP PROSERVE แต่ละชุดโดยอัตโนมัติ รหัสผ่านถูกเก็บแบบเข้ารหัส DPAPI",
+        "يطبق المُشغِّل تلقائياً نصوص SQL المرفقة في _migrations/ لكل ZIP من PROSERVE. كلمة المرور مُخزَّنة بتشفير DPAPI."
+    );
     public static string SettingsLanguage   => T("LANGUE",         "LANGUAGE",       "语言",          "ภาษา",          "اللغة");
     public static string SettingsLanguageHint => T(
         "Le launcher redémarrera pour appliquer le changement.",