fix(rotation): 回测导出JSON序列化NaN/Inf清洗

- simple_rotation.py: 新增 _sanitize_json() 递归替换 NaN/Inf 为 None，
  确保 json.dump 生成合法 JSON（避免前端解析失败）
- .env: 注释掉群2钉钉配置（暂不使用）

rotation/simple_rotation.py

@@ -40,6 +40,22 @@ def _http_get(url: str, params: dict = None, timeout: int = 120) -> requests.Res
     return _session.get(url, params=params, timeout=timeout)
 
 
+def _sanitize_json(obj):
+    """Recursively replace NaN/Inf with None in-place so json.dump produces valid JSON"""
+    if isinstance(obj, dict):
+        for k, v in obj.items():
+            if isinstance(v, float) and (math.isnan(v) or math.isinf(v)):
+                obj[k] = None
+            elif isinstance(v, (dict, list)):
+                _sanitize_json(v)
+    elif isinstance(obj, list):
+        for i, v in enumerate(obj):
+            if isinstance(v, float) and (math.isnan(v) or math.isinf(v)):
+                obj[i] = None
+            elif isinstance(v, (dict, list)):
+                _sanitize_json(v)
+
+
 # ============================================================
 # Pure functions: momentum
 # ============================================================
@@ -888,6 +904,7 @@ class SimpleRotationStrategy:
             },
             'days': days_out,
         }
+        _sanitize_json(detail)
         with open(detail_path, 'w', encoding='utf-8') as f:
             json.dump(detail, f, ensure_ascii=False, indent=2)
         print(f"  + Detail: {detail_path} ({len(days_out)} days)")
@@ -895,6 +912,7 @@ class SimpleRotationStrategy:
         # Metrics JSON
         metrics = self._compute_metrics(sum(1 for r in self.daily_records if r['is_rebalance']))
         metrics_path = output_dir / 'simple_rotation_metrics.json'
+        _sanitize_json(metrics)
         with open(metrics_path, 'w', encoding='utf-8') as f:
             json.dump(metrics, f, ensure_ascii=False, indent=2)
         print(f"  + Metrics: {metrics_path}")