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/backends.py

@@ -22,10 +22,11 @@ def numeric_engine_name(backend: str | None = None) -> str:
 
 
 def simulation_config(simulation) -> SolveIVPConfig:
-    # Preserve the existing XML execution accuracy. The XML
-    # protocol's future tolerance fields are a separate compatibility change.
+    # Match the validated native pipe/chamber accuracy. Per-state SI absolute
+    # floors are emitted by native_codegen.tolerances; XML tolerance fields
+    # remain a separate protocol change.
     return SolveIVPConfig(t_start=simulation.t_start, t_stop=simulation.t_stop,
-                         method=simulation.method, rtol=1e-6, max_step=simulation.max_step)
+                         method=simulation.method, rtol=1e-7, max_step=simulation.max_step)
 
 
 def simulate_network(network, simulation, *, progress_callback=None,