feat(hub): show cached monitor board when returning from market area

Co-authored-by: Cursor <cursoragent@cursor.com>

manual_trading_hub/static/app.css

@@ -160,6 +160,17 @@ a:hover {
   background: rgba(255, 77, 109, 0.1);
 }
 
+.sys-pill.syncing {
+  opacity: 0.85;
+  animation: sys-pill-pulse 1.2s ease-in-out infinite;
+}
+
+@keyframes sys-pill-pulse {
+  50% {
+    opacity: 0.55;
+  }
+}
+
 .top-nav {
   display: flex;
   gap: 4px;