fix: auto-save draft + API cleanup for editing flow (PR #1465)

- Step2/Step4 auto-save via useDraftAutoSave (GET-merge-PUT, serial queue)
- useDraftAutoSave: failed saves preserve patch with exponential backoff retry
- Step6 cover requests include full title_config
- Step7 create task: source_edit_plan_id, title_config, cover_url priority
- Polling switched to GET /generation/tasks/{task_id} with proper error handling
- getGenerationTaskResults retries before treating as failure
- Removed 7 ghost API functions (non-existent backend routes)
- BGM presets path updated to /templates/{id}/editor/bgm/presets
- Type alignment for BatchGenerationTaskResponse

apps/web/src/api/tasks/tasks.ts

@@ -6,6 +6,7 @@ import apiClient from "../client"
 import type {
   CreateGenerationTaskRequest,
   CreateGenerationTaskResponse,
+  GenerationTaskDetail,
   TaskItem,
   TaskListParams,
   TaskListResponse,
@@ -19,6 +20,12 @@ export const createGenerationTask = async (
   return data
 }
 
+/** 获取单个生成任务详情（轮询用） */
+export const getGenerationTask = async (taskId: string): Promise<GenerationTaskDetail> => {
+  const { data } = await apiClient.get<GenerationTaskDetail>(`/generation/tasks/${taskId}`)
+  return data
+}
+
 /** 获取任务列表（支持分页和筛选） */
 export const getTasks = async (params?: TaskListParams): Promise<TaskListResponse> => {
   const { data } = await apiClient.get<TaskListResponse>("/tasks", {

apps/web/src/api/tasks/types.ts

@@ -82,10 +82,12 @@ export interface CreateGenerationTaskRequest {
     stroke?: boolean
     shadow?: boolean
   }
+  /** 关联的草稿 ID（编辑流程数据链路用） */
+  source_edit_plan_id?: string
 }
 
-/** 创建生成任务响应（对齐后端 GenerationTaskResponse） */
-export interface CreateGenerationTaskResponse {
+/** 单个生成任务详情（对齐后端 GenerationTaskResponse） */
+export interface GenerationTaskDetail {
   id: string
   project_id: string
   asset_library_id: string
@@ -95,8 +97,18 @@ export interface CreateGenerationTaskResponse {
   asset_ids: string[]
   title_ids: string[]
   voice_ids: string[]
+  source_edit_plan_id?: string
   status: string
   progress: number
   result_count: number
   error_message: string
+  error_info?: TaskErrorInfo
+  created_at?: string | null
+  updated_at?: string | null
+}
+
+/** 创建生成任务响应（后端返回批量结构 {items, total}） */
+export interface CreateGenerationTaskResponse {
+  items: GenerationTaskDetail[]
+  total: number
 }