refactor: centralize numeric normalization

app/backend/features/screener/engine.py

@@ -9,6 +9,7 @@ from datetime import datetime, timedelta
 from typing import Any
 
 from advanced_strategies import ADVANCED_CURATED_STRATEGIES
+from backend.data.numbers import finite_number as _number
 from database import ReviewDatabase
 from backend.features.sentiment.engine import build_sentiment_history, latest_contiguous_history
 from tushare_client import TushareClient, TushareError
@@ -2201,13 +2202,5 @@ def _regime_reason(regime: str) -> str:
     }.get(regime, "市场阶段待确认。")
 
 
-def _number(value: Any, default: float = 0.0) -> float:
-    try:
-        number = float(value)
-        return number if math.isfinite(number) else default
-    except (TypeError, ValueError):
-        return default
-
-
 def _display_date(value: str) -> str:
     return f"{value[:4]}-{value[4:6]}-{value[6:8]}" if len(value) == 8 else value