fix(stats): 添加文件锁（fcntl.flock）防止并发竞态

- 添加 _acquire_lock() 和 _release_lock() 辅助函数
- _load_stats_data() 和 _atomic_write() 使用文件锁保护
- 使用独立的 .lock 文件作为锁
- 防止并发读写导致数据损坏

agents/haonan/workspace/dev-workflow/stats.py

@@ -8,6 +8,7 @@ Cross 模式统计报告模块
 import json
 import os
 import tempfile
+import fcntl
 from datetime import datetime
 from pathlib import Path
 from typing import Dict, List, Any, Optional
@@ -26,12 +27,32 @@ def _ensure_stats_dir():
     STATS_DIR.mkdir(parents=True, exist_ok=True)
 
 
+# 锁文件路径
+LOCK_FILE = STATS_DIR / "stats_data.lock"
+
+
+def _acquire_lock(lock_file_path: Path):
+    """获取文件锁"""
+    lock_file_path.parent.mkdir(parents=True, exist_ok=True)
+    lock_fd = open(lock_file_path, 'w')
+    fcntl.flock(lock_fd.fileno(), fcntl.LOCK_EX)
+    return lock_fd
+
+
+def _release_lock(lock_fd):
+    """释放文件锁"""
+    fcntl.flock(lock_fd.fileno(), fcntl.LOCK_UN)
+    lock_fd.close()
+
+
 def _load_stats_data() -> Dict[str, Any]:
-    """加载统计数据"""
+    """加载统计数据（带锁保护）"""
     if not STATS_FILE.exists():
         return {"events": [], "metadata": {"created_at": datetime.now().isoformat()}}
     
+    lock_fd = None
     try:
+        lock_fd = _acquire_lock(LOCK_FILE)
         with open(STATS_FILE, 'r', encoding='utf-8') as f:
             return json.load(f)
     except json.JSONDecodeError as e:
@@ -44,25 +65,40 @@ def _load_stats_data() -> Dict[str, Any]:
         return {"events": [], "metadata": {"created_at": datetime.now().isoformat()}}
     except IOError:
         return {"events": [], "metadata": {"created_at": datetime.now().isoformat()}}
+    finally:
+        if lock_fd:
+            _release_lock(lock_fd)
 
 
 def _atomic_write(data: Dict[str, Any]):
-    """原子写入统计数据"""
+    """原子写入统计数据（带锁保护）"""
     _ensure_stats_dir()
     
-    # 写入临时文件
-    fd, temp_path = tempfile.mkstemp(dir=STATS_DIR, suffix='.tmp')
+    lock_fd = None
+    temp_path = None
     try:
-        with os.fdopen(fd, 'w', encoding='utf-8') as f:
-            json.dump(data, f, ensure_ascii=False, indent=2)
+        lock_fd = _acquire_lock(LOCK_FILE)
+        
+        # 写入临时文件
+        with tempfile.NamedTemporaryFile(
+            mode='w', 
+            encoding='utf-8',
+            dir=STATS_DIR, 
+            suffix='.tmp',
+            delete=False
+        ) as temp_file:
+            json.dump(data, temp_file, ensure_ascii=False, indent=2)
+            temp_path = temp_file.name
         
         # 原子重命名
         os.replace(temp_path, STATS_FILE)
-    except Exception:
+        temp_path = None  # 防止在 finally 中再次删除
+    finally:
+        if lock_fd:
+            _release_lock(lock_fd)
         # 清理临时文件
-        if os.path.exists(temp_path):
+        if temp_path and os.path.exists(temp_path):
             os.unlink(temp_path)
-        raise
 
 
 def _filter_sensitive_data(data: Dict[str, Any]) -> Dict[str, Any]: