MOBILE_OVERVIEW_RUN_MODES / _buildMobileOverviewRunMenu is a separate,
hardcoded duplicate of the toolbar's #runModeMenu (mobile-overview.js
is a newer feature that mirrors the toolbar menu's look/behavior
rather than reusing its render), so it never picked up #201's
isCliAvailable() gating and offered every backend regardless of what
the server actually has installed.
Gate it the same way: skip an entry unless isCliAvailable(mode),
shell always exempt. Added functional + static regression tests
mirroring the toolbar menu's own test pattern.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>