优化原生结果编码传输与浏览器缓存，记录八路性能基线

原生结果series通过字节索引直传，C端使用Ryu精确回读编码和64 KiB批量写出；网页采用Float64缓存和CSV工作线程，减少结果处理与保存等待。

补充八路AME曲线核查、全流程分阶段计时、独立编码基准和复现工具，固定后续优化采用修正八路及rtol=1e-8。C写出1.1808→0.1638 s，点击到可查看8.0100→6.9756 s。

验证：最终10项编码专项、29项相关后端回归通过；8份原生结果逐位一致，16次网页结果/CSV/刷新恢复通过。前端构建及缓存/CSV专项在本轮结果处理工作中通过。环境、原始大结果与临时构建不纳入Git。

app/simulation/native_codegen/runner.py

@@ -12,13 +12,14 @@ import time
 
 from app.simulation.config import SolveIVPConfig
 from app.simulation.results import GenericSimulationResult
+from .transport import NativeSeriesJson, read_indexed_result
 from .build import NativeBuild, build_native
 from .compiler import NativeCapabilityError, compile_native_program
 
 
 def execute_native(build: NativeBuild, config: SolveIVPConfig, sample_step: float, *,
                    run_dir: Path, record_samples=True, cancel_check=None,
-                   progress_callback=None, activity_tracker=None, timeout=300.0) -> dict:
+                   progress_callback=None, activity_tracker=None, timeout=300.0, raw_series=False) -> dict:
     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:
@@ -26,13 +27,16 @@ def execute_native(build: NativeBuild, config: SolveIVPConfig, sample_step: floa
     run_dir.mkdir(parents=True, exist_ok=True)
     output = run_dir / "result.json"
     cancel_path = run_dir / "cancel.request"
-    if output.exists() or cancel_path.exists():
+    index_path = run_dir / "result-index.json"
+    if output.exists() or cancel_path.exists() or index_path.exists():
         raise ValueError("Native execution requires a fresh run directory.")
     command = [str(build.executable), "--method", config.method,
                "--start", str(config.t_start), "--stop", str(config.t_stop),
                "--sample-step", str(sample_step), "--max-step", str(config.max_step),
                "--rtol", str(config.rtol), "--timeout", str(timeout),
                "--cancel-file", str(cancel_path.resolve()), "--output", str(output.resolve())]
+    if raw_series:
+        command.extend(["--result-index", str(index_path.resolve())])
     if not record_samples:
         command.append("--solve-only")
     creationflags = subprocess.CREATE_NO_WINDOW if os.name == "nt" else 0
@@ -86,9 +90,13 @@ def execute_native(build: NativeBuild, config: SolveIVPConfig, sample_step: floa
             process.stderr.close()
     if not output.is_file():
         raise RuntimeError(f"Native worker exited with code {process.returncode} without results; see {run_dir / 'worker.log'}.")
-    payload = json.loads(output.read_text(encoding="utf-8"))
     if process.returncode not in (0, 2):
         raise RuntimeError(f"Native worker failed with exit code {process.returncode}.")
+    try:
+        payload = (read_indexed_result(output, index_path) if raw_series
+                   else json.loads(output.read_text(encoding="utf-8")))
+    except OSError as exc:
+        raise RuntimeError(f"Cannot read native worker result artifacts: {exc}") from exc
     payload["processWallSeconds"] = time.perf_counter()-started
     payload["buildKey"] = build.manifest["buildKey"]
     payload["cacheHit"] = build.cache_hit
@@ -99,7 +107,7 @@ def execute_native(build: NativeBuild, config: SolveIVPConfig, sample_step: floa
 
 
 def simulate_native(network, config, *, sample_step, progress_callback=None,
-                    cancel_check=None, activity_tracker=None):
+                    cancel_check=None, activity_tracker=None, raw_series=False):
     if config.method not in ("RK45", "BDF"):
         raise NativeCapabilityError(f"Native v1 does not support method {config.method}.")
     if progress_callback:
@@ -109,7 +117,7 @@ def simulate_native(network, config, *, sample_step, progress_callback=None,
     with tempfile.TemporaryDirectory(prefix="native-simulation-") as directory:
         data = execute_native(build, config, sample_step, run_dir=Path(directory),
                               cancel_check=cancel_check, progress_callback=progress_callback,
-                              activity_tracker=activity_tracker)
+                              activity_tracker=activity_tracker, raw_series=raw_series)
     totals = {
         "nfev": data["nfev"], "njev": data["njev"], "nlu": data["nlu"],
         "acceptedStepCount": data["acceptedSteps"], "rejectedStepCount": data["rejectedSteps"],
@@ -124,5 +132,6 @@ def simulate_native(network, config, *, sample_step, progress_callback=None,
         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, "rtol": config.rtol, "totals": totals},
-                     "stateCount": len(program.state_keys), "sampleCount": len(data["series"]["time"])},
+                     "stateCount": len(program.state_keys), "sampleCount": (data["series"].sample_count if isinstance(data["series"], NativeSeriesJson)
+                                     else len(data["series"].get("time", [])))},
     )