feat(web): AI 工作台多 task 串行推进与会话适配

- useWorkbenchAiApplicationPreviewFlow/useWorkbenchAiActionRouter/useWorkbenchAiCommandIntents 支持 task1 完成后自动推进 task2，确认按钮直接拉起申请预览，草稿/提交成功后继续推进下一 task
- workbenchAiIntentPlannerModel/workbenchAiMessageModel/workbenchAiCommandIntentModel 适配多 task 意图规划与消息结构
- aiApplicationPreviewActions/aiApplicationPrecheckModel/aiExpenseDraftModel/aiWorkbenchConversationStore 草稿与会话存储适配
- PersonalWorkbenchAiMode 与样式适配，更新 preview-actions/expense-draft/conversation-store/fast-preview/action-router/command-intent/intent-planner 测试

web/tests/workbench-ai-intent-planner-model.test.mjs

@@ -79,6 +79,48 @@ test('workbench AI intent planner normalizes model travel application submit pla
   })
 })
 
+test('workbench AI intent planner keeps reimbursement task after first application task', () => {
+  const reimbursementTask = {
+    task_id: 'task-reimbursement-2',
+    task_type: 'reimbursement',
+    assigned_agent: 'reimbursement_assistant',
+    title: '业务招待费报销',
+    summary: '报销昨天的业务招待费 2000 元',
+    requested_action: 'preview',
+    confidence: 0.9,
+    ontology_fields: {
+      expense_type: 'entertainment',
+      expense_type_label: '业务招待费',
+      time_range: '2026-06-25',
+      amount: '2000元',
+      reason: '业务招待'
+    },
+    missing_fields: []
+  }
+  const plan = normalizeWorkbenchAiIntentPlan({
+    planning_source: 'llm_function_call',
+    tasks: [{
+      task_id: 'task-application-1',
+      task_type: 'expense_application',
+      assigned_agent: 'application_assistant',
+      requested_action: 'preview',
+      confidence: 0.93,
+      ontology_fields: {
+        expense_type: 'travel',
+        time_range: '2026-02-20 至 2026-02-23',
+        location: '上海',
+        reason: '服务国网服务器部署'
+      },
+      missing_fields: ['transport_mode']
+    }, reimbursementTask]
+  }, {
+    prompt: '2月20-23日去上海出差3天，服务国网服务器部署，并且报销昨天的业务招待费2000元'
+  })
+
+  assert.deepEqual(plan.stewardRemainingTasks, [reimbursementTask])
+  assert.deepEqual(resolveExecutableTravelApplicationPlan(plan).stewardRemainingTasks, [reimbursementTask])
+})
+
 test('workbench AI intent planner prefers server action steps when present', () => {
   const plan = normalizeWorkbenchAiIntentPlan({
     planning_source: 'llm_function_call',
@@ -304,7 +346,12 @@ test('workbench AI mode asks steward model plan before fallback execution', () =
   assert.match(personalWorkbenchAiModeScript, /requestedSubmit:\s*travelApplicationRequest\.requestedSubmit/)
   assert.match(personalWorkbenchAiModeScript, /submitRequiresConfirmation:\s*travelApplicationRequest\.submitRequiresConfirmation/)
   assert.match(personalWorkbenchAiModeScript, /ontologyFields:\s*travelApplicationRequest\.ontologyFields/)
+  assert.match(personalWorkbenchAiModeScript, /stewardRemainingTasks:\s*travelApplicationRequest\.stewardRemainingTasks/)
+  assert.match(personalWorkbenchAiModeScript, /onPreviewReadyForNextTask:\s*startModelPlannedNextTask/)
+  assert.match(personalWorkbenchAiModeScript, /onApplicationActionCompleted:\s*startModelPlannedNextTask/)
   assert.match(applicationPreviewFlowScript, /options\.autoSaveDraft/)
+  assert.match(applicationPreviewFlowScript, /options\.onPreviewReadyForNextTask/)
+  assert.match(applicationPreviewFlowScript, /onApplicationActionCompleted\(\s*targetMessage\.stewardRemainingTasks/)
   assert.doesNotMatch(applicationPreviewFlowScript, /options\.autoSubmit && normalizeApplicationPreview\(preview\)\.readyToSubmit/)
   assert.match(applicationPreviewFlowScript, /ontologyFields:\s*options\.ontologyFields/)
   assert.match(applicationPreviewFlowScript, /executeInlineApplicationPreviewAction\(AI_APPLICATION_ACTION_SAVE_DRAFT/)