Code pill: six fixed cells on their own row, tap to copy, wrapping header; claim error names the length when it is not 6; board hint

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

public/app.js

@@ -36,7 +36,7 @@
       + '<p style="margin-top:10px"><span class="range">' + r.minPol + ' to ' + r.maxPol + ' POL</span> <span style="color:var(--dim);font-size:12px">· ' + m.dwell + 's on the site</span></p>'
       + (m.done ? '' : (board.pool && board.pool.spent && !isOpen) ? '<div style="margin-top:14px"><span class="tag gold">Closed until midnight Central</span></div>' : (board.daily && !board.daily.left && !isOpen) ? '<div style="margin-top:14px"><span class="tag">Back tomorrow</span></div>' : isOpen
         ? '<div class="timer" id="timer">Your code appears on the site after <b>' + m.dwell + 's</b>. Keep that tab open.</div>'
-          + '<div class="codebox"><input id="code" maxlength="6" placeholder="CODE" autocomplete="off" spellcheck="false"><button class="btn pol" id="submit">Claim</button></div>'
+          + '<div class="codebox"><input id="code" maxlength="6" placeholder="6 CHARACTERS" autocomplete="off" spellcheck="false" inputmode="text" autocapitalize="characters"><button class="btn pol" id="submit">Claim</button></div><div class="site" style="font-size:12px;margin-top:6px">Six characters. On the site, tap the code to copy it, then paste it here.</div>'
           + '<div class="msg" id="msg"></div>'
           + '<p style="margin-top:8px"><a href="' + esc(open.url) + '" target="_blank" rel="noopener">Open the site again ↗</a></p>'
         : '<div style="margin-top:14px"><button class="btn" data-start="' + esc(m.id) + '">Start mission</button></div>')