Add ESC key navigation support in settings menus

[bvdr]

Summary

Implement ESC key navigation support throughout the settings menu system to improve user experience and provide intuitive navigation.

Features

ESC Key Navigation

• Nested menus: Pressing ESC returns to parent menu
• Top-level menu: Pressing ESC exits settings entirely
• Exit option: Added explicit "← Exit Settings" and "← Back to Settings" options

Menu Flow Improvements

• Settings menu now loops - after completing an action, returns to settings menu
• Can navigate back from credential update submenu
• Clean exit messaging for better UX

Implementation Details

Files Modified

1. index.js
   • Wrapped showSettings() in a while(true) loop for continuous menu navigation
   • Added ESC handling with isCancel() checks and continue statements
   • Modified updateCredentials() to return navigation signals ('back', 'continue')
   • Added "← Exit Settings" option to main settings menu
   • Added "← Back to Settings" option to credential update submenu
   • All ESC presses return to previous menu level

User Experience Flow

1. Main Settings Menu → ESC exits settings
2. Credential Update Menu → ESC returns to settings
3. Provider Selection → ESC returns to settings
4. Model Selection → ESC returns to settings
5. After any action → Returns to settings menu automatically

Benefits

• Intuitive navigation matching standard UI patterns
• Users can easily navigate back without completing unwanted actions
• Better discoverability with explicit back/exit options
• Consistent behavior across all menu levels
• Reduced frustration from being "stuck" in menus

Acceptance Criteria

• ESC in top-level settings menu exits
• ESC in nested menus returns to parent
• Explicit back/exit options visible
• Settings loop after completing actions
• All menu flows tested

Related

Improves navigation and UX for settings management interface.