Smart LAN detection for sidebar service links

dashboard/frontend/src/components/Sidebar.svelte

@@ -11,6 +11,15 @@
     { id: "settings", label: "Settings", icon: "settings" },
   ];
 
+  const LAN_IP = "192.168.1.173";
+  let lanReachable = $state(false);
+
+  if (typeof window !== "undefined" && location.hostname !== LAN_IP) {
+    fetch(`http://${LAN_IP}:4000/`, { mode: "no-cors", signal: AbortSignal.timeout(1500) })
+      .then(() => { lanReachable = true; })
+      .catch(() => {});
+  }
+
   const external = [
     { label: "Navidrome", href: "https://music.jimmygan.com", icon: "music" },
     { label: "Immich", port: 2283, icon: "image" },
@@ -20,6 +29,9 @@
   ];
 
   function extHref(port) {
+    if (lanReachable && location.hostname !== LAN_IP) {
+      return `http://${LAN_IP}:${port}`;
+    }
     return `${location.protocol}//${location.hostname}:${port}`;
   }