Expose SDL_GamepadAxis as an Axis enum in GamepadManager so
QML can identify axis events by name.
Convert left-stick deflection into repeated grid navigation
events with a 150ms interval and 0.4 deadzone. First movement
fires immediately when the stick crosses the threshold.
Wrap game launches in a brief fade-to-black curtain (250ms)
before dismissing the overlay, giving visual feedback that the
launch is in progress.
SDL3-backed gamepad manager polls at 60Hz, handles hotplug,
exposes battery/rumble/LED per device. Game launcher aggregates
XDG desktop entries, Steam appmanifests, and Flatpak into a
single sorted model.
Game Center uses the new model instead of folio's search model.
D-pad/A/B/Y navigate and launch. Guide button toggles the
overlay. Battery and controller status shown in the HUD.
