fix: 修复统计日历 bootstrap 导致整站 500

日历数据改为安全 JSON 内嵌，仅统计页构建；构建失败时降级为空，避免拖垮其他页面。

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

tests/test_trade_stats_calendar_lib.py

@@ -3,7 +3,11 @@ from types import SimpleNamespace
 
 from datetime import datetime
 
-from trade_stats_calendar_lib import build_initial_stats_calendar, build_trade_stats_calendar
+from trade_stats_calendar_lib import (
+    build_initial_stats_calendar,
+    build_stats_calendar_bootstrap,
+    build_trade_stats_calendar,
+)
 
 
 def _row(**kwargs):
@@ -69,6 +73,18 @@ class TradeStatsCalendarLibTests(unittest.TestCase):
         self.assertEqual(payload["month_open_count"], 1)
         self.assertIn("2026-06-20", payload["days"])
 
+    def test_bootstrap_json_roundtrip(self):
+        pnls = [(2.5, None, "2026-06-20", _row())]
+        payload, raw = build_stats_calendar_bootstrap(
+            pnls,
+            datetime(2026, 6, 26, 12, 0),
+            _matches_all,
+            reset_hour=8,
+        )
+        self.assertIsNotNone(payload)
+        self.assertIsNotNone(raw)
+        self.assertIn('"month_open_count":1', raw.replace(" ", ""))
+
 
 if __name__ == "__main__":
     unittest.main()