Easter egg: give the mini-game a real mobile trigger

.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

src/components/Nav.js

@@ -1,6 +1,7 @@
 import { el } from '../lib/dom.js';
 import { openGameSheet } from './GameSheet.js';
 import { settings } from '../store/settings.js';
+import { onTapCode } from '../lib/tap-code.js';
 
 const ITEMS = [
   { label: 'Dex', icon: '▦', href: '#/', match: (h) => h === '#/' || h === '' || h === '#' },
@@ -25,20 +26,6 @@ export function Nav() {
   const nav = el('nav', { class: 'nav', 'aria-label': 'Primary' });
   let links = [];
 
-  // Easter egg: seven quick taps on the wordmark opens the hidden game
-  // (the Konami code does the same on a keyboard).
-  let taps = 0;
-  let tapTimer = null;
-  function bumpBrand() {
-    taps += 1;
-    clearTimeout(tapTimer);
-    tapTimer = setTimeout(() => (taps = 0), 1500);
-    if (taps >= 7) {
-      taps = 0;
-      location.hash = '#/whos-that';
-    }
-  }
-
   function build() {
     const st = settings.get();
     const items = ITEMS.filter((it) => !it.optional || st[it.optional]);
@@ -55,10 +42,13 @@ export function Nav() {
           )
         : el('a', { class: 'nav__link', href: item.href }, ...inner);
     });
-    nav.replaceChildren(
-      el('span', { class: 'nav__brand', onclick: bumpBrand }, 'Pocketdex'),
-      ...links,
-    );
+    // Easter egg: the wordmark only shows on wide screens; on mobile the
+    // same shortcut lives on the dex feed's game title (see DexGrid).
+    const brand = el('span', { class: 'nav__brand' }, 'Pocketdex');
+    onTapCode(brand, () => {
+      if ((location.hash || '') !== '#/whos-that') location.hash = '#/whos-that';
+    });
+    nav.replaceChildren(brand, ...links);
     nav._items = items;
     sync();
   }

src/lib/tap-code.js

@@ -0,0 +1,23 @@
+/**
+ * Fire `fn` after `count` taps/clicks land on `node` within `windowMs` of
+ * each other — a quiet way to hide a shortcut behind a bit of fidgeting.
+ * Returns an unbind.
+ */
+export function onTapCode(node, fn, { count = 7, windowMs = 1500 } = {}) {
+  let n = 0;
+  let timer = null;
+  const onClick = () => {
+    n += 1;
+    clearTimeout(timer);
+    timer = setTimeout(() => (n = 0), windowMs);
+    if (n >= count) {
+      n = 0;
+      fn();
+    }
+  };
+  node.addEventListener('click', onClick);
+  return () => {
+    clearTimeout(timer);
+    node.removeEventListener('click', onClick);
+  };
+}

src/views/DexGrid.js

@@ -8,6 +8,7 @@ import { Card } from '../components/Card.js';
 import { ProgressRing } from '../components/ProgressRing.js';
 import { Sprite } from '../components/Sprite.js';
 import { typesForGen } from '../lib/type-resolve.js';
+import { onTapCode } from '../lib/tap-code.js';
 
 const TYPES = [
   'normal',
@@ -429,16 +430,18 @@ export async function DexGrid() {
   }
   syncToolsBadge();
 
+  // Easter egg: a flurry of taps on the game title opens the hidden game.
+  // (The Konami code does the same with a keyboard.)
+  const feedId = el('div', { class: 'feed-head__id' }, title, gameLabel);
+  onTapCode(feedId, () => {
+    if ((location.hash || '') !== '#/whos-that') location.hash = '#/whos-that';
+  });
+
   view.append(
     el(
       'header',
       { class: 'feed-head' },
-      el(
-        'div',
-        { class: 'feed-head__top' },
-        el('div', { class: 'feed-head__id' }, title, gameLabel),
-        ring.node,
-      ),
+      el('div', { class: 'feed-head__top' }, feedId, ring.node),
       el(
         'div',
         { class: 'field-search' },

test/tap-code.test.js

@@ -0,0 +1,43 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { onTapCode } from '../src/lib/tap-code.js';
+
+const tap = (node) => node.dispatchEvent(new Event('click'));
+
+beforeEach(() => vi.useFakeTimers());
+afterEach(() => vi.useRealTimers());
+
+describe('onTapCode', () => {
+  it('fires after `count` taps inside the window', () => {
+    const node = new EventTarget();
+    const fn = vi.fn();
+    onTapCode(node, fn, { count: 7, windowMs: 1500 });
+    for (let i = 0; i < 6; i++) tap(node);
+    expect(fn).not.toHaveBeenCalled();
+    tap(node);
+    expect(fn).toHaveBeenCalledTimes(1);
+  });
+
+  it('resets when taps are too far apart', () => {
+    const node = new EventTarget();
+    const fn = vi.fn();
+    onTapCode(node, fn, { count: 3, windowMs: 500 });
+    tap(node);
+    tap(node);
+    vi.advanceTimersByTime(600); // window elapsed -> counter clears
+    tap(node);
+    tap(node);
+    expect(fn).not.toHaveBeenCalled();
+    tap(node);
+    expect(fn).toHaveBeenCalledTimes(1);
+  });
+
+  it('unbind stops it', () => {
+    const node = new EventTarget();
+    const fn = vi.fn();
+    const off = onTapCode(node, fn, { count: 2 });
+    off();
+    tap(node);
+    tap(node);
+    expect(fn).not.toHaveBeenCalled();
+  });
+});