feat: Implement the PolyWeather dashboard including frontend components, data collection, analysis, and API endpoints.

src/analysis/settlement_rounding.py

@@ -0,0 +1,20 @@
+import math
+from typing import Optional, Union
+
+
+Number = Union[int, float]
+
+
+def wu_round(value: Optional[Number]) -> Optional[int]:
+    """
+    WU 结算口径四舍五入（0.5 一律进位）:
+    - 正数: floor(x + 0.5)
+    - 负数: ceil(x - 0.5)
+    """
+    if value is None:
+        return None
+    x = float(value)
+    if x >= 0:
+        return int(math.floor(x + 0.5))
+    return int(math.ceil(x - 0.5))
+