feat(wechat): add subscribe morning reminder, plaza welcome, and LLM fallback

Enable daily morning greeting on reply 1 (with custom time, modify, and cancel),
random greeting delivery, M发现 in subscribe welcome, and optional LLM parsing when
rules miss. Also fix WeChat MP draft/config error passthrough and add Tang E2E scripts.

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

server.mjs

@@ -305,6 +305,7 @@ let systemDisclosurePolicyService = null;
 let agentCodeRunPolicyService = null;
 let wechatCursorExecutorPolicyService = null;
 let wechatScheduleLlmConfigService = null;
+let wechatSubscribeMorningLlmConfigService = null;
 let wechatScheduledTaskManageLlmConfigService = null;
 let wechatIntentRouter = null;
 let mindSpace = null;
@@ -540,6 +541,8 @@ async function bootstrapUserAuth() {
       memorySessionServices.wechatCursorExecutorPolicyService;
     wechatScheduleLlmConfigService =
       memorySessionServices.wechatScheduleLlmConfigService;
+    wechatSubscribeMorningLlmConfigService =
+      memorySessionServices.wechatSubscribeMorningLlmConfigService;
     wechatScheduledTaskManageLlmConfigService =
       memorySessionServices.wechatScheduledTaskManageLlmConfigService;
     wechatIntentRouter =
@@ -609,6 +612,7 @@ async function bootstrapUserAuth() {
         taskUnifiedService,
         sessionSnapshotService,
         wechatScheduleLlmConfigService,
+        wechatSubscribeMorningLlmConfigService,
         wechatScheduledTaskManageLlmConfigService,
         wechatIntentRouter,
         wechatCursorExecutorPolicyService,
@@ -1058,6 +1062,9 @@ function mindSpaceError(res, req, error) {
     empty_page_content: 400,
     static_page_not_found: 404,
     preview_not_supported: 422,
+    wechat_mp_not_configured: 400,
+    invalid_wechat_mp_config: 400,
+    wechat_draft_push_failed: 502,
   };
   const code = error?.code ?? 'internal_error';
   const status = statusByCode[code] ?? 500;