diff --git a/src/blackboard/models.py b/src/blackboard/models.py
index eb38649..617588a 100644
--- a/src/blackboard/models.py
+++ b/src/blackboard/models.py
@@ -39,6 +39,8 @@ class Task:
     stages_json: str = "[]"                   # 动态 Stage 定义（仅顶层 Task）
     # v3.1 暂停恢复
     resumed_from: Optional[str] = None       # 暂停前状态，恢复时回到原状态
+    # v2.9 四相循环
+    round_count: int = 0                     # 庞统 review 轮次计数
     # v2.8 归档
     archived: bool = False
     archived_at: Optional[str] = None