前端进度条性能优化、仿真结束后后处理优化；后端C代码生成流程优化：先识别来源，再按照已知未知量需求排序，最后局部求解

app/simulation/components/amesim/junctions/nodes.py

@@ -5,6 +5,7 @@ from app.simulation.core.base import AlgebraicComponent
 from app.simulation.core.catalog import ComponentDisplaySpec, PortDisplaySpec
 from app.simulation.core.medium import IdealGasMedium
 from app.simulation.core.ports import PortDefinition
+from app.simulation.core.port_computation import NODE_BRANCH, NODE_REFERENCE
 
 class _AmesimPneumaticNode(AlgebraicComponent):
     """Shared implementation for AMESim pneumatic junction submodels.
@@ -27,7 +28,7 @@ class AmesimPn3Node2(_AmesimPneumaticNode):
     """AMESim PN3NODE2 pneumatic three-port junction."""
     MODEL_TYPE = 'amesim_pn3node2'
     MODEL_VERSION = '0.3.0'
-    PORTS = (PortDefinition.pneumatic('port_1', nominal_role='bidirectional'), PortDefinition.pneumatic('port_2', nominal_role='bidirectional'), PortDefinition.pneumatic('port_3', nominal_role='bidirectional'))
+    PORTS = (PortDefinition.pneumatic('port_1', computation=NODE_BRANCH), PortDefinition.pneumatic('port_2', computation=NODE_REFERENCE), PortDefinition.pneumatic('port_3', computation=NODE_BRANCH))
     PARAMETERS = ()
     RESULT_VARIABLES = ()
     DISPLAY = ComponentDisplaySpec(label='PN3NODE2 三端气动节点', library_id='amesim', category_id='junctions', symbol='amesim_pn3node2', ports=(PortDisplaySpec('port_1', 'left', order=10), PortDisplaySpec('port_2', 'right', order=20), PortDisplaySpec('port_3', 'right', order=30)), order=10)
@@ -41,7 +42,7 @@ class AmesimP4Node2(_AmesimPneumaticNode):
     """AMESim P4NODE2 pneumatic four-port junction."""
     MODEL_TYPE = 'amesim_p4node2'
     MODEL_VERSION = '0.3.0'
-    PORTS = (PortDefinition.pneumatic('port_1', nominal_role='bidirectional'), PortDefinition.pneumatic('port_2', nominal_role='bidirectional'), PortDefinition.pneumatic('port_3', nominal_role='bidirectional'), PortDefinition.pneumatic('port_4', nominal_role='bidirectional'))
+    PORTS = (PortDefinition.pneumatic('port_1', computation=NODE_BRANCH), PortDefinition.pneumatic('port_2', computation=NODE_REFERENCE), PortDefinition.pneumatic('port_3', computation=NODE_BRANCH), PortDefinition.pneumatic('port_4', computation=NODE_BRANCH))
     PARAMETERS = ()
     RESULT_VARIABLES = ()
     DISPLAY = ComponentDisplaySpec(label='P4NODE2 四端气动节点', library_id='amesim', category_id='junctions', symbol='amesim_p4node2', ports=(PortDisplaySpec('port_1', 'left', order=10), PortDisplaySpec('port_2', 'right', order=20), PortDisplaySpec('port_3', 'right', order=30), PortDisplaySpec('port_4', 'right', order=40)), order=20)