opció de preset al service menu (params_file → params_preset)

Defaults::Settings::PARAMS_FILE passa a PARAMS_PRESET (id intern:
classic/arcade/red); director concatena .txt al carregar. Nou
ListOption "GAME_PRESET" al service menu amb les tres opcions
localitzades (cal reinici per aplicar). Validació al parser del YAML:
si el preset desat no existeix, cau al default.

source/game/ui/service_menu.cpp

@@ -541,6 +541,22 @@ void ServiceMenu::addSettingsOptions() {
             Options::checkPendingChanges();
         }));
 
+    // Preset de paràmetres (requereix reinici): cicla classic/arcade/red
+    std::vector<std::string> preset_display_names;
+    preset_display_names.reserve(Options::PARAMS_PRESETS.size());
+    std::ranges::transform(Options::PARAMS_PRESETS, std::back_inserter(preset_display_names), Options::getParamsPresetDisplayName);
+    options_.push_back(std::make_unique<ListOption>(
+        Lang::getText("[SERVICE_MENU] GAME_PRESET"),
+        SettingsGroup::SETTINGS,
+        preset_display_names,
+        []() -> std::string {
+            return Options::getParamsPresetDisplayName(Options::pending_changes.new_params_preset);
+        },
+        [](const std::string& val) -> void {
+            Options::pending_changes.new_params_preset = Options::getParamsPresetIdFromDisplay(val);
+            Options::checkPendingChanges();
+        }));
+
     options_.push_back(std::make_unique<BoolOption>(
         Lang::getText("[SERVICE_MENU] ENABLE_SHUTDOWN"),
         SettingsGroup::SETTINGS,