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-mp.mjs

@@ -3525,6 +3525,12 @@ export function createWechatMpService({
             wechatScheduleLlmConfigService,
             llmProviderService,
             logger,
+          }).catch((err) => {
+            logger.warn?.(
+              'WeChat MP schedule intent handling failed open:',
+              err instanceof Error ? err.message : err,
+            );
+            return null;
           })
         : null;
     if (scheduleReply) {