task-28: 死代码清理

删除拆分后失去引用的 API 残留文件：
- src/shared/api/call.ts（已由 http.ts 取代）
- src/shared/api/download.ts（已由 download-url.ts 取代）
- src/shared/api/status.ts（页面内已有本地实现）
及其孤儿测试 tests/call.test.ts / call-abort.test.ts / download.test.ts / status.test.ts。
endpoints/url/user 仍被模块文件引用，保留。

新增 8 个验证测试（dead-code-cleanup.test.ts）：无重复导出、
vue-tsc 零错误、全量测试绿、无调试日志、无残留函数体、
16+ HTML 入口存在、build 产物齐全、提交变更仅限 frontend-vue。

frontend-vue/src/shared/api/call.ts

@@ -1,35 +0,0 @@
-import { http, type RequestOptions } from './http.ts'
-
-export interface JavaApiResponse<T> {
-  success: boolean
-  message: string
-  data: T | null
-}
-
-export interface LegacyApiSuccess<T> {
-  success: true
-  msg?: string
-  data?: T
-}
-
-export async function callJava<T = unknown, D = unknown>(
-  config: RequestOptions<D>,
-): Promise<T> {
-  const body = await http.request<unknown, unknown, D>(config)
-  const data = (body as { data?: unknown }).data ?? body
-
-  if (
-    data &&
-    typeof data === 'object' &&
-    'success' in data &&
-    typeof (data as { success: unknown }).success === 'boolean'
-  ) {
-    const wrapped = data as { success: boolean; message?: string; msg?: string; error?: string; data?: T }
-    if (!wrapped.success) {
-      throw new Error(wrapped.message || wrapped.msg || wrapped.error || '请求失败')
-    }
-    return wrapped.data as T
-  }
-
-  return data as T
-}

frontend-vue/src/shared/api/download.ts

@@ -1,22 +0,0 @@
-export interface DownloadableItem {
-  freshDownloadUrl?: string | null
-  downloadUrl?: string | null
-}
-
-export function buildDownloadUrl(path: string, userId?: number): string {
-  if (userId === undefined || userId === null || Number.isNaN(userId)) {
-    return path
-  }
-  if (/[?&]user_id=/.test(path)) {
-    return path
-  }
-  const separator = path.includes('?') ? '&' : '?'
-  return `${path}${separator}user_id=${userId}`
-}
-
-export function resolveDownloadUrl(item: DownloadableItem | null | undefined): string {
-  if (!item) {
-    return ''
-  }
-  return item.freshDownloadUrl || item.downloadUrl || ''
-}

frontend-vue/src/shared/api/status.ts

@@ -1,26 +0,0 @@
-export function normalizeStatus(raw: string | null | undefined): string {
-  if (typeof raw !== 'string') {
-    return ''
-  }
-  const trimmed = raw.trim()
-  if (!trimmed) {
-    return ''
-  }
-  return trimmed.toUpperCase().replace(/[\s-]+/g, '_')
-}
-
-export function isTerminalStatus(
-  status: string | null | undefined,
-  extras?: string[],
-): boolean {
-  const normalized = normalizeStatus(status)
-  if (!normalized) {
-    return false
-  }
-  const terminalSet = new Set([
-    'SUCCESS',
-    'FAILED',
-    ...(extras ?? []).map((extra) => normalizeStatus(extra)),
-  ])
-  return terminalSet.has(normalized)
-}