让免费层限流的报告跟真实限流一致，并给少一块结果的静默失败留下函数名和错误类型。

Co-Authored-By: Grok (agent loop)

scripts/reference_transparency_contract.py

@@ -4,6 +4,7 @@
 from __future__ import annotations
 
 import json
+import logging
 import sys
 from datetime import datetime
 from functools import lru_cache
@@ -14,6 +15,8 @@ SCRIPT_DIR = Path(__file__).resolve().parent
 if str(SCRIPT_DIR) not in sys.path:
     sys.path.insert(0, str(SCRIPT_DIR))
 
+logger = logging.getLogger(__name__)
+
 try:
     from scripts.domain_calculation_service import compute_chart, compute_transit_longitude, compute_vimshottari_timeline
     from scripts.timing_precision_contract import build_timing_precision_contract
@@ -253,9 +256,11 @@ def _case_chart(case_id: str, year: int, month: int, day: int, hour: int, minute
     try:
         return compute_chart({
             "year": year, "month": month, "day": day, "hour": hour, "minute": minute,
-            "lat": lat, "lon": lon, "tz": tz, "ayanamsa": "lahiri", "node_mode": node_mode,
+            "lat": lat, "lon": lon, "tz": tz, "ayanamsa": "lahiri",             "node_mode": node_mode,
         })
-    except Exception:
+    except Exception as exc:
+        logger.warning("reference_transparency_contract._case_chart degraded: %s", type(exc).__name__)
+        logger.debug("reference_transparency_contract._case_chart degraded", exc_info=True)
         return None