升级外部生成为正式任务列表

将 external_generation_job 扩展为含价格、确认时间、退款流水和事件审计的正式生成任务事实源

新增外部生成任务列表与确认 BFF，并让平台入口按后端任务补弹完成或失败提示

保护画布生成队列超时、快照回写和自动保存覆盖场景

将 worker 计费退款流水写入 externalGenerationJobId，并补充冷备份后 worker/controller 恢复守护

packages/shared/src/contracts/externalGeneration.ts

@@ -7,6 +7,7 @@ export type ExternalGenerationJobStatus =
 export interface ExternalGenerationQueueOverview {
   pendingCount: number;
   runningCount: number;
+  unacknowledgedTerminalCount: number;
   updatedAtMicros: number;
 }
 
@@ -27,3 +28,37 @@ export interface ExternalGenerationJobStatusRecord {
 export interface ExternalGenerationJobStatusResponse {
   job: ExternalGenerationJobStatusRecord;
 }
+
+export interface ExternalGenerationTaskRecord {
+  jobId: string;
+  jobKind: string;
+  sourceModule: string;
+  sourceEntityId: string;
+  requestLabel: string;
+  status: ExternalGenerationJobStatus;
+  phaseLabel: string;
+  phaseDetail: string;
+  progress: number;
+  error?: string | null;
+  priceMudPoints: number;
+  refundLedgerId?: string | null;
+  notificationAcknowledgedAt?: string | null;
+  createdAt: string;
+  startedAt?: string | null;
+  completedAt?: string | null;
+  updatedAt: string;
+  updatedAtMicros: number;
+}
+
+export interface ExternalGenerationTaskListResponse {
+  tasks: ExternalGenerationTaskRecord[];
+  overview: ExternalGenerationQueueOverview;
+}
+
+export interface ExternalGenerationTaskAcknowledgeRequest {
+  jobIds: string[];
+}
+
+export interface ExternalGenerationTaskAcknowledgeResponse {
+  acknowledgedTasks: ExternalGenerationTaskRecord[];
+}