Reload controls after menu/boolean/button change

Switching a menu control (e.g. exposure auto → manual) changes the
flags on related controls (e.g. exposure_absolute loses FLAG_GRABBED).
Re-fetch and re-render controls silently after any non-slider change so
the updated enabled/read-only states are reflected immediately.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

dev/web/public/app.mjs

@@ -37,6 +37,7 @@ const CTRL_CLASSES = [
 const known_peers = new Map();   /* key: addr:name -> peer */
 let selected_peer        = null;
 let selected_device_idx  = null;
+let selected_device_path = null;
 let device_data          = null;
 
 /* -------------------------------------------------------------------------
@@ -245,6 +246,7 @@ function make_device_item(idx, path, label, device_caps, is_capture) {
 
 async function select_device(idx, path) {
 	selected_device_idx  = idx;
+	selected_device_path = path;
 	document.querySelectorAll('.device-item').forEach(el => {
 		el.classList.toggle('selected', parseInt(el.dataset.idx) === idx);
 	});
@@ -272,6 +274,20 @@ async function load_controls(device_idx, device_path) {
 	}
 }
 
+/* Silent reload — no loading flash; used after a control change that may
+ * alter other controls' flags (e.g. switching exposure mode ungrabs
+ * exposure_absolute). */
+async function reload_controls() {
+	if (selected_device_idx === null || selected_device_path === null) { return; }
+	try {
+		const result = await api('GET', `/api/devices/${selected_device_idx}/controls`);
+		by_id('controls-title').textContent = `Controls — ${selected_device_path}`;
+		render_controls(selected_device_idx, result.controls ?? []);
+	} catch (err) {
+		toast(err.message, 'err');
+	}
+}
+
 function render_controls(device_idx, controls) {
 	const scroll = by_id('controls-scroll');
 
@@ -377,10 +393,10 @@ function make_ctrl_row(device_idx, ctrl) {
 		};
 
 		if (ctrl.type === CTRL_BUTTON) {
-			input_el.addEventListener('click', send);
+			input_el.addEventListener('click', async () => { await send(); await reload_controls(); });
 		} else if (ctrl.type === CTRL_BOOLEAN || ctrl.type === CTRL_MENU
 				|| ctrl.type === CTRL_INTEGER_MENU) {
-			input_el.addEventListener('change', send);
+			input_el.addEventListener('change', async () => { await send(); await reload_controls(); });
 		} else {
 			input_el.addEventListener('pointerup', send);
 			input_el.addEventListener('keyup', send);