.nav__brand is display:none below 1024px, so "tap the wordmark" was
desktop-only. Add a shared onTapCode() helper (src/lib/tap-code.js) and
put the 7-tap shortcut on the dex feed's game-title (.feed-head__id),
which is visible on every screen size. Keeps the wordmark tap for desktop.
3 tests for onTapCode (count, window reset, unbind).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017Ve7HLspzeG2xDPtJQ8vmu
