feat(wechat): add Intent Transaction Layer with unified task schema

Introduce Draft → Confirm → Commit flow for WeChat schedule intents behind
feature flags, plus h5_tasks dual-write/read aggregation and rollout scripts
so reminders and automations get explicit user confirmation before persisting.

Co-authored-by: Cursor <cursoragent@cursor.com>

wechat-mp.mjs

@@ -28,6 +28,7 @@ import {
 } from './wechat/customer-service-deferred.mjs';
 import { guardScheduleConfirmationReply } from './wechat/handlers/schedule-guard.mjs';
 import { handleWechatScheduleIntent } from './wechat/handlers/schedule.mjs';
+import { handleWechatIntentTransaction } from './wechat/handlers/intent-transaction.mjs';
 import { handleWechatScheduledTaskIntent } from './wechat/handlers/scheduled-task.mjs';
 import {
   buildStatusText,
@@ -1598,6 +1599,8 @@ export function createWechatMpService({
   submitSessionReply = null,
   scheduleService = null,
   scheduledTaskService = null,
+  intentDraftService = null,
+  taskUnifiedService = null,
   wechatScheduleLlmConfigService = null,
   llmProviderService = null,
   chatIntentRouter = null,
@@ -3993,6 +3996,42 @@ export function createWechatMpService({
       };
     }
 
+    const intentTransactionReply =
+      intent.msgType === 'text' || intent.msgType === 'voice'
+        ? await handleWechatIntentTransaction({
+            intent,
+            user: boundUser,
+            intentDraftService,
+            taskUnifiedService,
+            scheduleService,
+            scheduledTaskService,
+            logger,
+          }).catch((err) => {
+            logger.warn?.(
+              'WeChat MP intent transaction handling failed open:',
+              err instanceof Error ? err.message : err,
+            );
+            return null;
+          })
+        : null;
+    if (intentTransactionReply) {
+      if (inbound.msgId && typeof userAuth.finishWechatMpMessage === 'function') {
+        await userAuth.finishWechatMpMessage({
+          appId: config.appId,
+          openid: inbound.fromUserName,
+          msgId: inbound.msgId,
+          status: 'done',
+          agentSessionId: null,
+        });
+      }
+      return {
+        ok: true,
+        status: 200,
+        contentType: 'application/xml; charset=utf-8',
+        body: await buildPassiveReplyBody(intentTransactionReply),
+      };
+    }
+
     const scheduledTaskReply =
       intent.msgType === 'text' || intent.msgType === 'voice'
         ? await handleWechatScheduledTaskIntent({