Move all C# scripts from flat structure to organized folders:
- Core/ for game logic (Game, GameState, GameSettings)
- UI/Menus/ and UI/Dialogs/ for user interface
- Systems/ for reusable systems (Save, Localization)
- Data/ for data models and configuration
- Added framework for future: Gameplay/, Story/, Modding/
Update all .tscn scene files to reference new script paths.
Fix timing issue in AdvancedSaveDialog focus handling.
- Implemented LocalizationManager for handling multiple languages.
- Updated LoadGameMenu, MainMenu, PauseMenu, and SettingsMenu to support localization.
- Added InstanceSelectionMenu for selecting game instances.
- Refactored SaveManager to handle new SaveInstance structure.
- Created SaveDialog for saving games with user-defined names.
- Enhanced SaveData to manage multiple save instances.
- Added error handling and logging for save/load operations.
- Updated UI elements to reflect localized text.
