feat(web): AI 意图规划置信度阈值与动作策略细化

- workbenchAiIntentPlannerModel 新增 WORKBENCH_AI_INTENT_CONFIDENCE_THRESHOLD 与 isLowConfidenceTravelApplicationPlan，shouldRequestWorkbenchAiIntentPlan 增加业务关键词前置过滤
- resolveExecutableTravelApplicationPlan 区分 requestedSubmit 与提交确认（submitRequiresConfirmation），autoSubmit 不再直接置真
- workbenchIntentActionPolicy 改用 policyDecision 路由（need_confirmation/query_candidates），透传 riskLevel/requiresSelection/requiresConfirmation
- workbenchIntentFrameModel 补充 query 动作识别，usePersonalWorkbenchAiMode/useWorkbenchAiActionRouter/useWorkbenchAiApplicationPreviewFlow 接入低置信度与确认流程
- 更新 intent-planner-model/intent-frame-model/application-gate-model/fast-preview 测试

web/tests/workbench-ai-application-gate-model.test.mjs

@@ -41,9 +41,11 @@ test('workbench application gate detects compact travel application direct submi
     expenseType: 'travel',
     expenseTypeLabel: '差旅费',
     sourceText: '去上海出差，辅助国网仿生产服务器部署，交通火车，直接提交',
-    autoSubmit: true
+    autoSubmit: false,
+    requestedSubmit: true
   })
   assert.equal(resolveInlineTravelApplicationRequest('去上海出差，辅助国网仿生产服务器部署，交通火车')?.autoSubmit, false)
+  assert.equal(resolveInlineTravelApplicationRequest('去上海出差，辅助国网仿生产服务器部署，交通火车')?.requestedSubmit, false)
   assert.equal(resolveInlineTravelApplicationRequest('帮我查询上海差旅标准'), null)
 })