高温氦气物性补全；三通四通能量计算bug修正

app/simulation/native_codegen/tolerances.py

@@ -13,4 +13,6 @@ def state_absolute_tolerance(key: str) -> str:
         return '1e-14'  # kg
     if field in ('v', 'x'):
         return '1e-12'  # m/s or m
+    if field == '_volume_displacement':
+        return '1e-14'  # m3, prescribed external volume change
     return '1e-8'  # J (or the internal constant state of an algebraic model)