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.

data/lang/en_UK.json

@@ -104,6 +104,10 @@
     "[SERVICE_MENU] EASY": "Easy",
     "[SERVICE_MENU] NORMAL": "Normal",
     "[SERVICE_MENU] HARD": "Hard",
+    "[SERVICE_MENU] GAME_PRESET": "Preset",
+    "[SERVICE_MENU] PRESET_CLASSIC": "Classic",
+    "[SERVICE_MENU] PRESET_ARCADE": "Arcade",
+    "[SERVICE_MENU] PRESET_RED": "Red",
     "[SERVICE_MENU] NEED_RESTART_MESSAGE": "Restart to apply changes",
     "[SERVICE_MENU] ENABLE_SHUTDOWN": "Allow system shutdown",
     "[SERVICE_MENU] CONTROLS": "Controls",