[Nevrdid]

Summary

• Introduce explicit Home / Library / Details / All ROMs navigation state.
• Add a themed home page with entry points to the game library, recent games, All ROMs, overall statistics, and Add Game.
• Recent games reuses the current library renderer and filters to games with at least one recorded play session.
• Add a filesystem-backed All ROMs browser that scans the portable Roms/ folder or /mnt/SDCARD/Roms on TrimUI, skips hidden paths, and opens/tracks a selected ROM.
• Return from the library to Home with B; keep X as the Details-to-Library shortcut.
• Extract Add Game into a reusable action for the home page and existing menu.
• Reuse the current SDL renderer and theme assets instead of importing the old MyUI page framework.
• Document the navigation responsibilities and incremental plan in docs/ui-navigation.md.

Scope

This establishes the presentation and initial page organization while reusing the current data and rendering layers. Collections and settings remain out of scope until their behavior is defined. The ROM browser deliberately avoids guessing emulator-specific extension lists.

Validation

• Native x86-64 build and smoke tests are running in GitHub Actions.
• Runtime behavior on a physical TrimUI device still needs manual verification.