Fix WS connected indicator and restore ref import in TVView

Use connected ref directly from useWebSocket instead of copying the value,
so the Live/Reconnecting indicator updates reactively. Restore ref import
that was incorrectly removed (still needed for the clock).

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

frontend/src/views/TVView.vue

@@ -100,11 +100,9 @@ const currentSubjectName = computed(() =>
 )
 
 // WebSocket
-const wsConnected = ref(false)
+const { connected: wsConnected } = useWebSocket(childId, (msg) => {
-const { connected } = useWebSocket(childId, (msg) => {
   scheduleStore.applyWsEvent(msg)
 })
-wsConnected.value = connected.value
 
 // Initial data load
 onMounted(async () => {