style: rename Stopp button to Stop

app/static/app.js

@@ -51,7 +51,7 @@ function render() {
       : '';
     const track = el('p', 'track', zone.error || trackText);
     const controls = el('div', 'controls');
-    for (const [icon, label, action] of [['▶','Play','play'], ['■','Stopp','stop']]) {
+    for (const [icon, label, action] of [['▶','Play','play'], ['■','Stop','stop']]) {
       const button = el('button', action === 'play' ? 'stacked-play' : null);
       if (action === 'play') button.append(el('span', 'play-icon', icon), el('span', null, label));
       else button.textContent = `${icon} ${label}`;