Debug mode (alt mode) gets stuck when Alt-Tabbing

[joeyfoo]

TL:DR Description: Alt keystroke conflicts with Alt-Tab.
Suggestion: Change the debug hotkey or reset the debug state when clicking on a different stop

Reproduced in Microsoft Edge Dev 86.0.601.1

---

Long story: I was wondering why the Passing Routes and Bus Arrivals buttons were randomly replaced by the Set as Start and Set as End buttons. Dug into the code, and I eventually found out that the Alt keystroke is used to toggle the alt-mode class.

Turns out what was happening was the down keystroke for the Alt key would fire when switching with Alt-Tab, but the key up event wouldn't be captured while out of focus.