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

src/components/platform-entry/PlatformEntryFlowShellImpl.test.ts

@@ -69,6 +69,7 @@ describe('buildExternalGenerationQueueStatus', () => {
         {
           pendingCount: 7,
           runningCount: 3,
+          unacknowledgedTerminalCount: 1,
           updatedAtMicros: 1_781_222_400_000_000,
         },
         {
@@ -85,6 +86,8 @@ describe('buildExternalGenerationQueueStatus', () => {
       currentProgress: 35,
       pendingCount: 7,
       runningCount: 3,
+      unacknowledgedTerminalCount: 1,
+      tasks: null,
     });
   });
 
@@ -99,6 +102,7 @@ describe('buildExternalGenerationQueueStatus', () => {
         currentProgress: 42.4,
         pendingCount: 2,
         runningCount: 1,
+        unacknowledgedTerminalCount: 0,
       }),
     ).toEqual({
       statusLabel: '生成中',
@@ -107,7 +111,9 @@ describe('buildExternalGenerationQueueStatus', () => {
       runningLabel: '1',
       pendingCount: 2,
       runningCount: 1,
+      unacknowledgedTerminalCount: 0,
       progress: 42,
+      tasks: [],
       shouldShow: true,
     });