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/core/processing/processor_manager.py

@@ -11,6 +11,7 @@ from wled_controller.core.devices.led_client import (
     DeviceHealth,
     check_device_health,
     create_led_client,
+    get_device_capabilities,
     get_provider,
 )
 from wled_controller.core.audio.audio_capture import AudioCaptureManager
@@ -810,6 +811,11 @@ class ProcessorManager:
         state = self._devices.get(device_id)
         if not state:
             return
+        # Skip periodic health checks for virtual devices (always online)
+        if "health_check" not in get_device_capabilities(state.device_type):
+            from datetime import datetime
+            state.health = DeviceHealth(online=True, latency_ms=0.0, last_checked=datetime.utcnow())
+            return
         if state.health_task and not state.health_task.done():
             return
         state.health_task = asyncio.create_task(self._health_check_loop(device_id))