feat(web): AI 工作台意图规划与规划思考模型

- 新增 workbenchAiIntentPlannerModel，基于 LLM function_call 解析建单/草稿/提交意图，区分 model 与 rule_fallback 来源
- 新增 workbenchAiPlanningThinkingModel 合并规划思考事件流，按 eventId 去重合并
- application gate/preview 模型接入意图规划，usePersonalWorkbenchAiMode/useWorkbenchAiStewardFlow/useWorkbenchAiActionRouter 链路适配，支持上下文提交
- steward 服务与 stewardPlanModel 适配新动作结构，receipt-folder-view 微调样式
- 新增 intent-planner-model/application-context-submit/steward-actions-service 测试，更新 gate-model/action-router/plan-message-copy/fast-preview 测试

web/src/services/steward.js

@@ -24,6 +24,14 @@ export function fetchStewardRuntimeDecision(payload, options = {}) {
   })
 }
 
+export function executeStewardAction(payload, options = {}) {
+  return apiRequest('/steward/actions/execute', {
+    method: 'POST',
+    body: JSON.stringify(payload),
+    ...options
+  })
+}
+
 export async function fetchStewardPlanStream(payload, handlers = {}, options = {}) {
   const {
     timeoutMs = 0,