fix(wechat): guard ambiguous memory recall and scheduled task execution

Skip memory injection for short filler messages, demote page-workflow memory
pollution, keep scheduled automation off page.generate, and fail scheduled
tasks that only return clarification instead of deliverables.

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

wechat/wechat-channel.test.mjs

@@ -33,6 +33,15 @@ test('classifyWechatIntent detects page.generate', () => {
   assert.equal(isPageGenerateIntent({ msgType: 'text', agentText: intent.topic }), true);
 });
 
+test('classifyWechatIntent keeps scheduled automation on chat.general', () => {
+  const intent = classifyWechatIntent({
+    msgType: 'text',
+    agentText: '我想创建一个定时执行任务，今晚 21:45 分执行做新闻页面',
+  });
+  assert.equal(intent.kind, 'chat.general');
+  assert.equal(isPageGenerateIntent({ msgType: 'text', agentText: intent.text }), false);
+});
+
 test('classifyWechatIntent detects session.reset', () => {
   assert.equal(classifyWechatIntent({ msgType: 'text', agentText: '换话题' }).kind, 'session.reset');
   assert.equal(classifyWechatIntent({ msgType: 'text', agentText: '换新会话' }).kind, 'session.reset');