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/workbenchIntentActionPolicy.js

@@ -10,13 +10,21 @@ export function resolveWorkbenchIntentActionRoute(frame = null) {
   if (frame.action === 'ask_policy') {
     return { nextStep: 'pass_through' }
   }
-  if (frame.targetMode === 'current_context' && frame.safetyLevel === 'confirm_required') {
-    return { nextStep: 'open_context_confirm' }
+  if (frame.policyDecision === 'need_confirmation') {
+    return {
+      nextStep: 'open_context_confirm',
+      riskLevel: frame.riskLevel,
+      requiresSelection: Boolean(frame.requiresSelection),
+      requiresConfirmation: Boolean(frame.requiresConfirmation)
+    }
   }
-  if (frame.targetMode === 'filtered_candidates' && QUERY_CANDIDATE_ACTIONS.has(frame.action)) {
+  if (frame.policyDecision === 'query_candidates' && QUERY_CANDIDATE_ACTIONS.has(frame.action)) {
     return {
       nextStep: 'query_candidates',
-      queryPrompt: frame.normalizedQuery || ''
+      queryPrompt: frame.normalizedQuery || '',
+      riskLevel: frame.riskLevel,
+      requiresSelection: Boolean(frame.requiresSelection),
+      requiresConfirmation: Boolean(frame.requiresConfirmation)
     }
   }
   return { nextStep: 'pass_through' }