v2.17.3

Release v2.17.3

release-check: OK 0c56507

Changelog

Burger tap target on phones

Fixed

• Burger (.nowo-ui-burger, app shell and _burger partials): flex-shrink: 0 and a 32×32px minimum, so a
  crowded phone header (a flex row with min-width: 0) no longer squeezes it to its 20px glyph. A regression test also
  pins the skip link to the theme's surface / text pair, which keeps it readable in dark themes.