task-106(任务与重复分析中心): 实现视频任务批量下载任务

新增 image-video-download.ts(选择键解析/打包请求体/响应头计数/下载 job 状态)，
image-video-api.ts 增加 requestVideoZipDownload(POST /download-zip, blob)。

TDD: task-106.test.ts 8 用例先 RED 后 GREEN。

admin-frontend-vue/src/pages/tasks/image-video-api.ts

@@ -1,7 +1,8 @@
-/** 视频任务列表/详情适配（任务 103/104）：GET /api/admin/image-video-tasks(/detail)。 */
+/** 视频任务列表/详情/批量下载适配（任务 103-106）。 */
 import { http } from '@/api/http'
 import { parseImageVideoDetail, parseImageVideoPage, type ImageVideoDetail, type ImageVideoPageResult } from './image-video-model.ts'
 import { toImageVideoQuery, type ImageVideoFilter } from './image-video-filter.ts'
+import { downloadZipHeaderCounts, toVideoZipRequest } from './image-video-download.ts'
 
 export const IMAGE_VIDEO_TASKS_ENDPOINT = '/api/admin/image-video-tasks'
 
@@ -21,3 +22,18 @@ export async function fetchImageVideoTaskDetail(taskId: string | number): Promis
   const { data } = await http.get<unknown>(`${IMAGE_VIDEO_TASKS_ENDPOINT}/${taskId}`)
   return parseImageVideoDetail(data)
 }
+
+export interface VideoZipDownloadResult {
+  blob: Blob
+  fileCount?: number
+  errorCount?: number
+}
+
+/** 批量打包下载视频：POST /download-zip(blob)；从响应头读成功/失败计数。 */
+export async function requestVideoZipDownload(keys: readonly string[]): Promise<VideoZipDownloadResult> {
+  const { data, headers } = await http.post<Blob>(`${IMAGE_VIDEO_TASKS_ENDPOINT}/download-zip`, toVideoZipRequest(keys), {
+    responseType: 'blob',
+  })
+  const counts = downloadZipHeaderCounts(headers as Record<string, string>)
+  return { blob: data, fileCount: counts.fileCount, errorCount: counts.errorCount }
+}

admin-frontend-vue/src/pages/tasks/image-video-download.ts

@@ -0,0 +1,72 @@
+/** 视频批量打包下载任务模型（任务 106）：选择键→打包请求体、下载 job 状态与响应头计数；纯逻辑。 */
+
+export type BatchDownloadStatus = 'idle' | 'running' | 'done' | 'failed'
+
+export interface BatchDownloadJob {
+  status: BatchDownloadStatus
+  message?: string
+  fileCount?: number
+  errorCount?: number
+}
+
+/** 解析 "taskId:videoIndex" 卡片选择键；非法键返回 null。 */
+export function parseVideoSelectionKey(key: string): { taskId: number; videoIndex: number } | null {
+  const match = /^(\d+):(\d+)$/.exec(typeof key === 'string' ? key.trim() : '')
+  if (!match) return null
+  return { taskId: Number(match[1]), videoIndex: Number(match[2]) }
+}
+
+/** 选择键 → POST /download-zip 请求体(去重、跳过非法键)。 */
+export function toVideoZipRequest(keys: readonly string[]): { items: Array<{ task_id: number; video_index: number }> } {
+  const items: Array<{ task_id: number; video_index: number }> = []
+  const seen = new Set<string>()
+  for (const key of keys) {
+    const parsed = parseVideoSelectionKey(key)
+    if (!parsed) continue
+    const token = `${parsed.taskId}:${parsed.videoIndex}`
+    if (seen.has(token)) continue
+    seen.add(token)
+    items.push({ task_id: parsed.taskId, video_index: parsed.videoIndex })
+  }
+  return { items }
+}
+
+/** 大小写不敏感解析 zip 响应头里的成功/失败计数。 */
+export function downloadZipHeaderCounts(headers: Record<string, string | number | undefined> | undefined): { fileCount?: number; errorCount?: number } {
+  const read = (name: string): number | undefined => {
+    if (!headers || typeof headers !== 'object') return undefined
+    const lower = name.toLowerCase()
+    for (const key of Object.keys(headers)) {
+      if (key.toLowerCase() === lower) {
+        const value = headers[key]
+        if (typeof value === 'number' && Number.isFinite(value)) return Math.floor(value)
+        if (typeof value === 'string' && /^\d+$/.test(value.trim())) return Number(value.trim())
+        return undefined
+      }
+    }
+    return undefined
+  }
+  const fileCount = read('x-archive-file-count')
+  const errorCount = read('x-archive-error-count')
+  if (fileCount === undefined && errorCount === undefined) return {}
+  const counts: { fileCount?: number; errorCount?: number } = {}
+  if (fileCount !== undefined) counts.fileCount = fileCount
+  if (errorCount !== undefined) counts.errorCount = errorCount
+  return counts
+}
+
+export function createBatchDownloadJob(): BatchDownloadJob {
+  return { status: 'idle' }
+}
+
+export function startBatchDownload(job: BatchDownloadJob): BatchDownloadJob {
+  return { status: 'running' }
+}
+
+export function succeedBatchDownload(job: BatchDownloadJob, fileCount: number, errorCount: number): BatchDownloadJob {
+  return { status: 'done', fileCount, errorCount }
+}
+
+export function failBatchDownload(job: BatchDownloadJob, message: string): BatchDownloadJob {
+  return { status: 'failed', message }
+}