Add spotify queue

static/panel.css

@@ -133,6 +133,7 @@ svg { width: 22px; height: 22px; fill: currentColor; }
 .ghost { background: transparent; border: 1px solid var(--outline); color: var(--muted); box-shadow: none; }
 
 @keyframes spin { to { transform: rotate(360deg); } }
+@keyframes blink { 0%, 80%, 100% { opacity: .2; } 40% { opacity: 1; } }
 @keyframes rise { from { transform: translateY(100%); opacity: .4; } }
 
 /* Header */
@@ -302,6 +303,38 @@ header .logo { height: 44px; width: auto; display: block; margin: var(--space-xs
 
 .toggle .leave { display: none; }
 
+/* Card - Spotify Queue */
+
+.queue { background: var(--shade); border-radius: var(--radius-lg); }
+.queue summary {
+  display: flex; align-items: center; justify-content: space-between; gap: var(--space-md);
+  min-height: 44px; padding: 0 var(--space-md);
+  font-size: var(--text-sm); font-weight: 600; color: var(--muted);
+  list-style: none; cursor: pointer;
+}
+.queue summary::-webkit-details-marker { display: none; }
+.queue-label { display: flex; align-items: center; gap: var(--space-sm); }
+.queue-label svg { width: 16px; height: 16px; }
+.queue summary .chevron { width: 16px; height: 16px; transition: transform .2s ease-out; }
+.queue[open] summary .chevron { transform: rotate(90deg); }
+
+.queue-list {
+  list-style: none; margin: 0;
+  padding: 0 var(--space-md) var(--space-md);
+  display: flex; flex-direction: column; gap: var(--space-sm);
+}
+.queue-item { display: flex; align-items: center; gap: var(--space-md); min-width: 0; }
+.queue-item .cover { width: 40px; height: 40px; border-radius: 8px; }
+.queue-item .track { flex: 1; }
+.queue-item .song { font-size: var(--text-sm); }
+.queue-item .artist { font-size: var(--text-xs); }
+.queue-time { flex: 0 0 auto; font-size: var(--text-xs); color: var(--muted); font-variant-numeric: tabular-nums; }
+.queue-note { font-size: var(--text-sm); color: var(--muted); }
+.queue-loading { display: block; width: 28px; height: 28px; margin: 0 auto; }
+.queue-loading path { animation: blink 1.2s ease-in-out infinite; }
+.queue-loading path:nth-child(2) { animation-delay: .2s; }
+.queue-loading path:nth-child(3) { animation-delay: .4s; }
+
 /* Card - AVR Input */
 
 .input-select {