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/tests/steward-actions-service.test.mjs

@@ -0,0 +1,54 @@
+import assert from 'node:assert/strict'
+
+import { executeStewardAction } from '../src/services/steward.js'
+
+async function testExecuteStewardActionUsesActionEndpoint() {
+  let capturedUrl = ''
+  let capturedOptions = null
+
+  global.fetch = async (url, options) => {
+    capturedUrl = String(url)
+    capturedOptions = options
+    return {
+      ok: true,
+      async json() {
+        return {
+          action_type: 'save_application_draft',
+          status: 'succeeded',
+          message: '申请草稿已保存。',
+          result_payload: {
+            draft_payload: {
+              claim_id: 'claim-action-draft',
+              claim_no: 'A12345678',
+              status: 'draft'
+            }
+          }
+        }
+      }
+    }
+  }
+
+  const payload = await executeStewardAction({
+    action_type: 'save_application_draft',
+    message: '保存草稿',
+    task: {
+      task_id: 'task-app-1',
+      task_type: 'expense_application'
+    }
+  })
+
+  assert.equal(capturedUrl, '/api/v1/steward/actions/execute')
+  assert.equal(capturedOptions.method, 'POST')
+  assert.equal(JSON.parse(capturedOptions.body).action_type, 'save_application_draft')
+  assert.equal(payload.status, 'succeeded')
+}
+
+async function run() {
+  await testExecuteStewardActionUsesActionEndpoint()
+  console.log('steward actions service tests passed')
+}
+
+run().catch((error) => {
+  console.error(error)
+  process.exit(1)
+})