feat: 完善架构优化性能

- 调整音视频架构，提升 RKMPP 编码 MJPEG-->H264 性能，同时解决丢帧马赛克问题；
- 删除多用户逻辑，只保留单用户，支持设置 web 单会话；
- 修复删除体验不好的的回退逻辑，前端页面菜单位置微调；
- 增加 OTG USB 设备动态调整功能；
- 修复 mdns 问题，webrtc 视频切换更顺畅。

web/src/api/request.ts

@@ -6,6 +6,7 @@ const API_BASE = '/api'
 // Toast debounce mechanism - prevent toast spam (5 seconds)
 const toastDebounceMap = new Map<string, number>()
 const TOAST_DEBOUNCE_TIME = 5000
+let sessionExpiredNotified = false
 
 function shouldShowToast(key: string): boolean {
   const now = Date.now()
@@ -81,7 +82,26 @@ export async function request<T>(
     // Handle HTTP errors (in case backend returns non-2xx)
     if (!response.ok) {
       const message = getErrorMessage(data, `HTTP ${response.status}`)
-      if (toastOnError && shouldShowToast(toastKey)) {
+      const normalized = message.toLowerCase()
+      const isNotAuthenticated = normalized.includes('not authenticated')
+      if (response.status === 401 && !sessionExpiredNotified) {
+        const isLoggedInElsewhere = normalized.includes('logged in elsewhere')
+        const isSessionExpired = normalized.includes('session expired')
+        if (isLoggedInElsewhere || isSessionExpired) {
+          sessionExpiredNotified = true
+          const titleKey = isLoggedInElsewhere ? 'auth.loggedInElsewhere' : 'auth.sessionExpired'
+          if (toastOnError && shouldShowToast('error_session_expired')) {
+            toast.error(t(titleKey), {
+              description: message,
+              duration: 3000,
+            })
+          }
+          setTimeout(() => {
+            window.location.reload()
+          }, 1200)
+        }
+      }
+      if (toastOnError && shouldShowToast(toastKey) && !(response.status === 401 && isNotAuthenticated)) {
         toast.error(t('api.operationFailed'), {
           description: message,
           duration: 4000,
@@ -130,4 +150,3 @@ export async function request<T>(
     throw new ApiError(0, t('api.networkError'))
   }
 }
-