/**
 * Scrollable device/group list with a fixed add row (dropdown + button) below.
 * Used by group and zone edit modals.
 */
function prepareZoneDevicesPanel(containerEl) {
    if (!containerEl) return null;
    let listEl = containerEl.querySelector('.zone-devices-list');
    let addSlot = containerEl.querySelector('.zone-devices-add-slot');
    if (!listEl) {
        containerEl.innerHTML = '';
        containerEl.classList.add('zone-devices-panel');
        listEl = document.createElement('div');
        listEl.className = 'zone-devices-list';
        addSlot = document.createElement('div');
        addSlot.className = 'zone-devices-add-slot';
        containerEl.appendChild(listEl);
        containerEl.appendChild(addSlot);
    } else {
        listEl.innerHTML = '';
        addSlot.innerHTML = '';
    }
    return { listEl, addSlot };
}

if (typeof window !== 'undefined') {
    window.prepareZoneDevicesPanel = prepareZoneDevicesPanel;
}