feat: bills expense type filter (backend join + frontend Select), sync stub docs

apps/server/src/sync/sync.service.ts

@@ -157,10 +157,11 @@ export class SyncService {
       this.logger.warn('DingTalk not configured (DINGTALK_APP_KEY missing), skipping sync');
       return 0;
     }
-
-    this.logger.warn(
-      'DingTalk integration service not yet implemented — add DingTalkService to SyncModule to enable real sync',
-    );
+    // 接入指引：
+    // 1. 创建 apps/server/src/integration/dingtalk.service.ts，实现 fetchDepartments()/fetchUsers()
+    // 2. 在 SyncModule 中注入 DingTalkService
+    // 3. 取消以下注释并调用 this.dingTalkService.fetchDepartments()
+    this.logger.warn('DingTalk sync stub: create DingTalkService in src/integration/ to enable real sync');
     return 0;
   }