fix: 修复无信号状态同步与采集管线阻塞

- 使用非阻塞 V4L2 句柄并类型化采集错误
- 完善视频管线生命周期，避免复用停止中的管线
- 区分音视频事件并支持 REST/WebSocket 状态快照
- 修复信号丢失后保留最后一帧及刷新后黑屏问题
- 优化无信号提示、状态展示优先级及相关界面细节
- 降低重复 OTG 错误日志级别

web/src/views/ConsoleView.vue

@@ -27,7 +27,7 @@ import { formatFpsValue } from '@/lib/fps'
 import { videoDebugLog } from '@/lib/debugLog'
 import { formatVideoDeviceLabel } from '@/lib/video-device-label'
 import { isAudioDeviceLostStateReason, isAudioStreamDeviceLostPayload } from '@/lib/streamSignal'
-import type { StreamDeviceLostEventData } from '@/types/websocket'
+import type { StreamDeviceLostEventData, StreamStateChangedEventData } from '@/types/websocket'
 import type { VideoMode } from '@/components/VideoConfigPopover.vue'
 
 import StatusCard, { type StatusDetail } from '@/components/StatusCard.vue'
@@ -1356,7 +1356,7 @@ function handleStreamModeSwitching(data: { transition_id: string; to_mode: strin
   videoSession.onModeSwitching(data)
 }
 
-function handleStreamStateChanged(data: any) {
+function handleStreamStateChanged(data: StreamStateChangedEventData) {
   videoDebugLog('Stream state changed event', {
     data,
     videoMode: videoMode.value,
@@ -1468,8 +1468,8 @@ const signalOverlayInfo = computed(() => {
     case 'no_signal':
       return {
         title: t('console.signal.noSignal.title'),
-        detail: t('console.signal.noSignal.detail'),
-        hint,
+        detail: hint || t('console.signal.noSignal.detail'),
+        hint: '',
         tone: 'info' as const,
       }
     case 'device_lost':
@@ -3083,6 +3083,10 @@ onMounted(async () => {
   }, { immediate: true })
 
   await systemStore.startStream().catch(() => {})
+  const initialStreamStatus = await streamApi.status().catch(() => null)
+  if (initialStreamStatus) {
+    handleStreamStateChanged(initialStreamStatus)
+  }
   await systemStore.fetchSystemInfo().catch(() => {})
   await systemStore.fetchAllStates()
   await configStore.refreshHid().then(() => {
@@ -3398,7 +3402,7 @@ onUnmounted(() => {
           </div>
           <Transition name="fade">
             <div
-              v-if="videoLoading"
+              v-if="videoLoading && !showSignalOverlay && !videoError"
               class="absolute inset-0 flex flex-col items-center justify-center bg-black/70 backdrop-blur-sm transition-opacity duration-300"
             >
               <div class="absolute inset-0 overflow-hidden pointer-events-none">
@@ -3443,7 +3447,7 @@ onUnmounted(() => {
           </Transition>
           <Transition name="fade">
             <div
-              v-if="showSignalOverlay && !videoLoading && !videoError"
+              v-if="showSignalOverlay && !videoError"
               class="absolute inset-0 flex flex-col items-center justify-center gap-3 p-4 transition-opacity duration-300 pointer-events-none"
               :class="{
                 'bg-black/80 backdrop-blur-sm': signalOverlayInfo.tone === 'error',

web/src/views/SettingsView.vue

@@ -2717,7 +2717,6 @@ watch(isWindows, () => {
       <Sidebar class="top-10 h-[calc(100dvh-2.5rem)] sm:top-14 sm:h-[calc(100dvh-3.5rem)]" collapsible="offcanvas">
         <SidebarHeader class="gap-1 px-6 pt-4 pb-2 text-foreground md:pt-6">
           <h1 class="text-xl font-semibold">{{ t('settings.title') }}</h1>
-          <p class="text-xs text-muted-foreground">{{ t('settings.sidebarSubtitle') }}</p>
         </SidebarHeader>
         <SidebarContent class="px-3 pb-6 md:pb-10">
           <SidebarGroup v-for="group in navGroups" :key="group.title" class="px-0 py-1">