Fix — Keyboard layout bug + arrow key support — Bulletreign: Survivors Steam update #1738373

Some players (notably Cyrillic ЙЦУКЕН — Ukraine/Russia — and AZERTY — France/Belgium — layouts) reported movement keys not working at all. Cause: movement was read from the *character a key produces*, which differs on those layouts, so the vehicle never moved. This build reads movement from the **physical key position** (`e.code`) instead, so the physical WASD position works on any layout/language (QWERTY unchanged). Adds **arrow key** support (↑ ↓ ← →) alongside WASD, and fixes a **stuck key** after the Steam Overlay (Shift+Tab) / Alt-Tab where the vehicle would drift on its own.