feat(ui): hide device management behind ⚙ MANAGE toggle — form and remove buttons only shown when active

lightsync/frontend/app.js

@@ -115,11 +115,18 @@ function escapeHtml(str) {
 
 loadDevices();
 
+document.getElementById("devices-manage-toggle").addEventListener("click", () => {
+    const panel = document.getElementById("devices-panel");
+    const btn = document.getElementById("devices-manage-toggle");
+    const active = panel.classList.toggle("manage-active");
+    btn.classList.toggle("active", active);
+});
+
 document.getElementById("add-device-form").addEventListener("submit", async (e) => {
     e.preventDefault();
     const form = e.target;
     const data = {
-        name: form.name.value.trim(),
+        name: form.elements["name"].value.trim(),
         strip_type: form.strip_type.value,
         led_count: parseInt(form.led_count.value, 10),
         ip: form.ip.value.trim(),