fix: keep the postgres backfill from disabling telemetry or locking the table

src/polygateway/pricing.py

@@ -47,6 +47,8 @@ class PricingTable:
     def __init__(self, prices: Mapping[str, ModelPrice]) -> None:
         self._prices = dict(prices)
         self._warned: set[str] = set()
+        # 独立集合: 与"未知 model"的告警去重键分开,避免 model 名恰好撞上时互相抑制
+        self._warned_clamp: set[str] = set()
 
     @classmethod
     def from_file(cls, path: Path | str) -> PricingTable:
@@ -111,9 +113,8 @@ class PricingTable:
         """命中数按输入总数夹取: 网关口径异常不得算出负成本(每 model 只警告一次)。"""
         if cached <= prompt_tokens:
             return cached
-        key = f"{model}:cached_over_prompt"
-        if key not in self._warned:
-            self._warned.add(key)
+        if model not in self._warned_clamp:
+            self._warned_clamp.add(model)
             logger.warning(
                 "model {!r} 上报的缓存命中 {} 超过输入总数 {},按总数夹取计价",
                 model,