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/native_codegen/runner.py

@@ -22,7 +22,7 @@ def execute_native(build: NativeBuild, config: SolveIVPConfig, sample_step: floa
     if config.method not in ("RK45", "BDF"):
         raise NativeCapabilityError(f"Native v1 does not support method {config.method}.")
     if not isinstance(config.atol, (int, float)) or config.atol != 1e-8 or config.first_step is not None:
-        raise NativeCapabilityError("Native v1 uses the existing default gas/mechanical absolute tolerances and automatic initial step.")
+        raise NativeCapabilityError("Native uses generated per-state absolute tolerances and automatic initial step; custom config.atol/first_step are not supported.")
     run_dir.mkdir(parents=True, exist_ok=True)
     output = run_dir / "result.json"
     cancel_path = run_dir / "cancel.request"
@@ -123,6 +123,6 @@ def simulate_native(network, config, *, sample_step, progress_callback=None,
         simulated_until=data["simulatedUntil"], requested_stop_time=config.t_stop,
         variables=program.variables, series=data["series"], final=data["final"],
         diagnostics={"backend": "native-c", "native": {k: v for k, v in data.items()
-                     if k not in ("series", "final", "finalState")}, "integration": {"method": config.method, "totals": totals},
+                     if k not in ("series", "final", "finalState")}, "integration": {"method": config.method, "rtol": config.rtol, "totals": totals},
                      "stateCount": len(program.state_keys), "sampleCount": len(data["series"]["time"])},
     )