This adds a fourth front button layout option where navigation buttons
(Left/Right) are placed in the center with Back on the far left and
Confirm on the far right, providing an alternative for users who prefer
this arrangement.
Changes:
- Added BACK_LEFT_RIGHT_CONFIRM enum value to FRONT_BUTTON_LAYOUT
- Updated MappedInputManager to handle button mapping for new layout
- Added 'Bck, Lft, Rght, Cnfrm' option to settings UI
- Updated USER_GUIDE.md to document the new option
## Summary
* Swap to updated SDCardManager which uses SdFat
* Add exFAT support
* Swap to using FsFile everywhere
* Use newly exposed `SdMan` macro to get to static instance of
SDCardManager
* Move a bunch of FsHelpers up to SDCardManager
## Summary
**What is the goal of this PR?**
Adds a setting to swap the front buttons. The default functionality are:
Back/Confirm/Left/Right. When this setting is enabled they become:
Left/Right/Back/Confirm. This makes it more comfortable to use when
holding in your right hand since your thumb can more easily rest on the
next button. The original firmware has a similar setting.
**What changes are included?**
- Add the new setting.
- Create a mapper to dynamically switch the buttons based on the
setting.
- Use mapper on the various activity screens.
- Update the button hints to reflect the swapped buttons.
## Additional Context
Full disclosure: I used Codex CLI to put this PR together, but did
review it to make sure it makes sense.
Also tested on my device:
https://share.cleanshot.com/k76891NY
