优化仿真求解性能并修复流量闭合问题（初版）

app/simulation/core/base.py

@@ -21,6 +21,13 @@ if TYPE_CHECKING:
 class Component(ABC):
     MODEL_TYPE: ClassVar[str | None] = None
     MODEL_VERSION: ClassVar[str | None] = None
+    # ``True`` means that pressure/flow residuals read values written by
+    # ``update_stream_outflows`` or ``update_flow_temperature_references``.
+    # ``False`` is an explicit promise that those residuals are independent of
+    # stream propagation.  ``None`` keeps custom components conservative: when
+    # they override either stream hook, the closure planner retains the legacy
+    # full-network thermofluid fixed point.
+    PRESSURE_FLOW_DEPENDS_ON_STREAM: ClassVar[bool | None] = None
     PORTS: ClassVar[tuple[PortDefinition, ...]] = ()
     PARAMETERS: ClassVar[tuple[ParameterDefinition, ...]] = ()
     RESULT_VARIABLES: ClassVar[tuple[ResultVariableDefinition, ...]] = ()