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/src/composables/workbenchAiMode/useWorkbenchAiApplicationPreviewFlow.js

@@ -195,6 +195,9 @@ export function useWorkbenchAiApplicationPreviewFlow({
     if (normalized.validationIssues?.length || normalized.missingFields?.length) {
       return buildApplicationPreviewFooterMessage(normalized)
     }
+    if (message?.submitRequiresConfirmation) {
+      return '已识别到您希望直接提交。系统不会自动提交申请，请先核对申请核对表；确认无误后，点击下方“直接提交”按钮再进入提交确认。'
+    }
     return '申请核对表已补齐，费用测算已同步。您仍可点击表格继续修改；确认无误后，可以点击下方按钮保存草稿或直接提交，也可以直接回复“保存草稿”或“提交”。'
   }
 
@@ -547,6 +550,8 @@ export function useWorkbenchAiApplicationPreviewFlow({
         id: pendingMessage.id,
         applicationPreview: preview,
         suggestedActions: buildInlineApplicationPreviewSuggestedActions(preview),
+        requestedSubmit: Boolean(options.requestedSubmit),
+        submitRequiresConfirmation: Boolean(options.submitRequiresConfirmation),
         stewardPlan: {
           streamStatus: 'completed',
           thinkingEvents: completeInlineThinkingEvents(resolveInlineThinkingEvents(pendingMessage))
@@ -554,13 +559,7 @@ export function useWorkbenchAiApplicationPreviewFlow({
         text: content
       })
       replaceInlineMessage(pendingMessage.id, previewMessage)
-      if (options.autoSubmit && normalizeApplicationPreview(preview).readyToSubmit) {
-        await executeInlineApplicationPreviewAction(AI_APPLICATION_ACTION_SUBMIT, previewMessage, {
-          confirmed: true,
-          skipUserMessage: true,
-          userText: options.userMessage || '直接提交'
-        })
-      } else if (options.autoSaveDraft) {
+      if (options.autoSaveDraft) {
         await executeInlineApplicationPreviewAction(AI_APPLICATION_ACTION_SAVE_DRAFT, previewMessage, {
           skipUserMessage: true,
           userText: options.userMessage || '保存草稿'