fix AVR input swap

static/app.js

@@ -61,6 +61,7 @@ els('.room').forEach((node) => {
     toggle: el('[data-role="group"]', node),
     toggleLabel: el('[data-role="group-label"]', node),
     play: el('[data-role="play"]', node),
+    next: el('[data-role="next"]', node),
     steps: els('.step', node),
     volume: null,
     playState: null,
@@ -80,6 +81,7 @@ els('.room').forEach((node) => {
 
   room.toggle.addEventListener('click', () => setGrouped(key, !room.grouped));
   room.play.addEventListener('click', () => togglePlay(key));
+  room.next.addEventListener('click', () => skipTrack(key));
 });
 
 function paintRoom(room) {
@@ -93,6 +95,12 @@ function paintRoom(room) {
   room.play.disabled = !room.available || room.playState === null;
   room.play.setAttribute(
     'aria-label', `${room.node.querySelector('h2').textContent}: ${playing ? 'pause' : 'play'}`);
+  // Grouped, transport belongs to the AVR's card, not this one -- pressing
+  // either here would still work (it shares the group's transport) but
+  // only invites confusion about which card is actually in charge of it.
+  room.play.hidden = room.grouped;
+  room.next.hidden = !playing || room.grouped;
+  room.next.disabled = !room.available;
 
   room.toggle.disabled = !room.available;
   room.toggle.classList.toggle('busy', room.busy);
@@ -225,6 +233,18 @@ async function togglePlay(key) {
   }
 }
 
+/* Fire-and-forget: the queue's next track has no local state to reconcile,
+   so there is nothing to optimistically flip the way play/pause does. */
+async function skipTrack(key) {
+  const room = rooms[key];
+  if (!room.available) return;
+  try {
+    await api('/api/skip', { target: key, direction: 'next' });
+  } catch (error) {
+    toast(error.message);
+  }
+}
+
 function applyJoined(joined) {
   Object.values(rooms).forEach((room) => {
     room.grouped = joined.includes(room.key);