feat: Implement multi-source weather data collection with caching, rate limiting, and disk persistence.

src/analysis/settlement_rounding.py

@@ -18,3 +18,24 @@ def wu_round(value: Optional[Number]) -> Optional[int]:
         return int(math.floor(x + 0.5))
     return int(math.ceil(x - 0.5))
 
+
+def is_exact_settlement_city(city: str) -> bool:
+    """是否为不四舍五入的精确结算城市"""
+    if not city:
+        return False
+    c = str(city).lower().strip()
+    return c in ["hong kong", "hk", "taipei", "tpe", "臺北", "台北", "香港"]
+
+
+def apply_city_settlement(city: str, value: Optional[Number]) -> Optional[int]:
+    """
+    根据城市返回最终的结算值：
+    - 香港/台北: 向下取整 (e.g. 28.9 -> 28)
+    - 其他: WU 规则四舍五入
+    """
+    if value is None:
+        return None
+    if is_exact_settlement_city(city):
+        return int(math.floor(float(value)))
+    return wu_round(value)
+