What changed in v5.2.3

Mobile-web support — the game now plays in a phone browser:

MobileWeb settings preset — a new shipped preset targets the phone-browser (WASM) build: it enables the on-screen touch pad on top of a low-cost 480p-window / 720p-render display profile. Distinct from Mobile, which stays reserved for native Android/iOS builds.
Debug-UI touch button — the on-screen pad gains a fourth row-3 button, "UI", that toggles the entire ImGui debug layer on/off. It drives a new global toggle_debug_ui action (also bound to F1 on desktop) that is never player-prefixed, so the one shared overlay flips regardless of which player's pad it lives on. A touch device with no keyboard can now dismiss the debug panels.
Touch button font fix — button labels now use PixeloidSans. The geometric arrow glyphs (▲▼◀▶) are not in Godot's built-in fallback font and previously rendered as tofu boxes; PixeloidSans covers both the arrows and the ASCII labels (CAM/MAP/RSP/UI).
Touch test coverage — a new automated test enables the pad, holds a real touch on the throttle button, and asserts the car reaches driving speed and travels.