Add cross-link to Turtle Dashboard in App component

web/client/src/App.jsx

@@ -22,6 +22,8 @@ function App() {
   const [showSettings, setShowSettings] = useState(false);
   const [, forceRender] = useState(0);
 
+  const turtleDashboardUrl = import.meta.env.VITE_TURTLE_DASHBOARD_URL || `${window.location.protocol}//${window.location.hostname}:4444`;
+
   useEffect(() => {
     connect();
   }, [connect]);
@@ -34,10 +36,6 @@ function App() {
 
   const staleSecs = lastUpdate ? Math.floor((Date.now() - lastUpdate) / 1000) : null;
 
-  useEffect(() => {
-    connect();
-  }, [connect]);
-
   const renderPanelContent = () => {
     switch (panelTab) {
       case 'inventory':
@@ -60,6 +58,16 @@ function App() {
       <div className="app-header">
         <h1>⛏️ Inventory Manager</h1>
         <div className="header-right">
+          {/* Cross-link to Turtle Dashboard */}
+          <a
+            href={turtleDashboardUrl}
+            className="cross-link-btn"
+            title="Open Turtle Control Dashboard"
+            target="_blank"
+            rel="noopener noreferrer"
+          >
+            🐢 Turtles
+          </a>
           {/* Settings gear button */}
           <button
             className="settings-gear"