Add WebSocket device type, capability-driven settings, hide filter on collapse

- New WS device type: broadcaster singleton + LEDClient that sends binary
  frames to connected WebSocket clients during processing
- FastAPI WS endpoint at /api/v1/devices/{device_id}/ws with token auth
- Frontend: add/edit WS devices, connection URL with copy button in settings
- Add health_check and auto_restore capabilities to WLED and Serial providers;
  hide health interval and auto-restore toggle for devices without them
- Skip health check loop for virtual devices (Mock, MQTT, WS) — set always-online
- Copy buttons and labels for API CSS push endpoints (REST POST / WebSocket)
- Hide mock:// and ws:// URLs in target device dropdown
- Hide filter textbox when card section is collapsed (cs-collapsed CSS class)

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

server/src/wled_controller/static/js/features/device-discovery.js

@@ -6,7 +6,7 @@ import {
     _discoveryScanRunning, set_discoveryScanRunning,
     _discoveryCache, set_discoveryCache,
 } from '../core/state.js';
-import { API_BASE, fetchWithAuth, isSerialDevice, isMockDevice, isMqttDevice, escapeHtml } from '../core/api.js';
+import { API_BASE, fetchWithAuth, isSerialDevice, isMockDevice, isMqttDevice, isWsDevice, escapeHtml } from '../core/api.js';
 import { t } from '../core/i18n.js';
 import { showToast } from '../core/ui.js';
 import { Modal } from '../core/modal.js';
@@ -76,6 +76,17 @@ export function onDeviceTypeChanged() {
         if (sendLatencyGroup) sendLatencyGroup.style.display = '';
         if (discoverySection) discoverySection.style.display = 'none';
         if (scanBtn) scanBtn.style.display = 'none';
+    } else if (isWsDevice(deviceType)) {
+        urlGroup.style.display = 'none';
+        urlInput.removeAttribute('required');
+        serialGroup.style.display = 'none';
+        serialSelect.removeAttribute('required');
+        ledCountGroup.style.display = '';
+        baudRateGroup.style.display = 'none';
+        if (ledTypeGroup) ledTypeGroup.style.display = 'none';
+        if (sendLatencyGroup) sendLatencyGroup.style.display = 'none';
+        if (discoverySection) discoverySection.style.display = 'none';
+        if (scanBtn) scanBtn.style.display = 'none';
     } else if (isSerialDevice(deviceType)) {
         urlGroup.style.display = 'none';
         urlInput.removeAttribute('required');
@@ -338,6 +349,8 @@ export async function handleAddDevice(event) {
     let url;
     if (isMockDevice(deviceType)) {
         url = 'mock://';
+    } else if (isWsDevice(deviceType)) {
+        url = 'ws://';
     } else if (isSerialDevice(deviceType)) {
         url = document.getElementById('device-serial-port').value;
     } else {
@@ -349,7 +362,7 @@ export async function handleAddDevice(event) {
         url = 'mqtt://' + url;
     }
 
-    if (!name || (!isMockDevice(deviceType) && !url)) {
+    if (!name || (!isMockDevice(deviceType) && !isWsDevice(deviceType) && !url)) {
         error.textContent = t('device_discovery.error.fill_all_fields');
         error.style.display = 'block';
         return;