Icons in the installed PWA were overlapped by the iOS home indicator and a
body-colored gap appeared between the nav bar and the executor status bar
(whose `bottom` already includes safe-area-inset-bottom + standalone-bottom-gap).
Adding matching `padding-bottom` to `.mobile-nav-bar` lifts icons above the
indicator and closes the gap.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>