Improve interactions to hide/show the footer

This fixes a few different usability issues with the footer:

- When tapping one of the footer buttons, the footer would be dismissed rather than activating the button.
- When the footer was hidden, you could still tap the buttons.
- Interacting with controls in the footer would not reset the timer that hides it, leading to a feeling that the footer can disappear out from under you.

src/room/InCallView.module.css

@@ -66,7 +66,6 @@ Please see LICENSE in the repository root for full details.
 .footer.overlay.hidden {
   display: grid;
   opacity: 0;
-  pointer-events: none;
 }
 
 .footer.overlay:has(:focus-visible) {