Refresh UI and improve Finder automation

• Restyle the main, settings, and credential setup views with reusable glass-style components
• Improve the AppleScript DMG path by explicitly requesting and mapping Finder Automation permission states before layout work begins, with clearer user-facing errors
• Improved log/stage presentation, and updated window sizing
• Add app language selection backed by AppleLanguages, plus new German, French, and Italian localizations
• Update the README and screenshots to document the new UI and automation behavior