fix(web): 统一 API 请求语义并修复鼠标移动发送间隔

- 新增统一 request：同时处理 HTTP 非 2xx 与 success=false，并用 i18n toast 提示错误
- api/index.ts 与 api/config.ts 统一使用同一 request，避免错误处理不一致
- "发送间隔" 仅控制鼠标移动事件频率，WebRTC/WS 行为一致，不影响点击/滚轮

web/src/api/index.ts

@@ -1,97 +1,9 @@
 // API client for One-KVM backend
 
-import { toast } from 'vue-sonner'
+import { request, ApiError } from './request'
 
 const API_BASE = '/api'
 
-// Toast debounce mechanism - prevent toast spam (5 seconds)
-const toastDebounceMap = new Map<string, number>()
-const TOAST_DEBOUNCE_TIME = 5000
-
-function shouldShowToast(key: string): boolean {
-  const now = Date.now()
-  const lastToastTime = toastDebounceMap.get(key)
-
-  if (!lastToastTime || now - lastToastTime >= TOAST_DEBOUNCE_TIME) {
-    toastDebounceMap.set(key, now)
-    return true
-  }
-
-  return false
-}
-
-class ApiError extends Error {
-  status: number
-
-  constructor(status: number, message: string) {
-    super(message)
-    this.name = 'ApiError'
-    this.status = status
-  }
-}
-
-async function request<T>(
-  endpoint: string,
-  options: RequestInit = {}
-): Promise<T> {
-  const url = `${API_BASE}${endpoint}`
-
-  try {
-    const response = await fetch(url, {
-      ...options,
-      headers: {
-        'Content-Type': 'application/json',
-        ...options.headers,
-      },
-      credentials: 'include',
-    })
-
-    // Parse response body (all responses are 200 OK with success field)
-    const data = await response.json().catch(() => ({
-      success: false,
-      message: 'Failed to parse response'
-    }))
-
-    // Check success field - all errors are indicated by success=false
-    if (data && typeof data.success === 'boolean' && !data.success) {
-      const errorMessage = data.message || 'Operation failed'
-      const apiError = new ApiError(response.status, errorMessage)
-
-      console.info(`[API] ${endpoint} failed:`, errorMessage)
-
-      // Show toast notification to user (with debounce)
-      if (shouldShowToast(`error_${endpoint}`)) {
-        toast.error('Operation Failed', {
-          description: errorMessage,
-          duration: 4000,
-        })
-      }
-
-      throw apiError
-    }
-
-    return data
-  } catch (error) {
-    // Network errors or JSON parsing errors
-    if (error instanceof ApiError) {
-      throw error // Already handled above
-    }
-
-    // Network connectivity issues
-    console.info(`[API] Network error for ${endpoint}:`, error)
-
-    // Show toast for network errors (with debounce)
-    if (shouldShowToast('network_error')) {
-      toast.error('Network Error', {
-        description: 'Unable to connect to server. Please check your connection.',
-        duration: 4000,
-      })
-    }
-
-    throw new ApiError(0, 'Network error')
-  }
-}
-
 // Auth API
 export const authApi = {
   login: (username: string, password: string) =>