Per-ROM Settings, Layout Scaling & External Display Logic

This version expands customization and display flexibility, adding per-ROM external display settings, custom ROM naming, and smarter layout scaling.
It also improves multi-display handling, this and has been successfully tested on the Ayaneo Pocket DS.

New Features

1. Per-ROM External Display & Layout Settings

• Users can now configure external screen mode and layout per ROM.
• Added support for:
  • externalScreen: Top, Bottom, or Custom
  • externalLayoutId: custom layout ID for external screen
• UI includes new selectors and layout pickers (ExternalLayoutSelectorActivity and Fragment).
• If no per-ROM setting is found, the app falls back to global preferences.

2. Layout Scaling

• If an exact layout match for the current screen size isn’t available, the app will now scale a matching layout variant (based on orientation).
• Enables better reusability of existing layouts across various resolutions.

3. Custom ROM Names

• Users can now set a custom name per ROM (displayed in list and emulator UI).
• Includes:
  • "ROM Display Name" setting in ROM config
  • Option to show filename instead of ROM title in general settings
  • Support for editing/deleting via TextInputDialog

Improvements & Fixes

• App now detects if it was launched on the external screen and adjusts presentation target accordingly:
  • If launched on internal screen → targets external display
  • If launched on external display → targets internal screen
• This replaces the previous behavior that forced the app to run only on the primary display.