修复循环信号与事件采样并接入 LSTP 接触定位，补充八路验证及复用实验

相较上一版 Jacobian 确定性复用更新，本次补齐事件边界一致性、结果两侧采样及接触事件定位；保留已有物性复用和组件力学公式。

- 统一 UD00 信号求值与下一事件查询的绝对时间边界，修复循环边界浮点舍入导致的阶段错位、重复或漏报，并覆盖零时长、多阶段及长周期场景。
- 引入原生输出语义 v2：保留规则网格真实时间，补充内部时间事件和状态事件的左邻及事件后采样，按保存时间、状态和离散模式重放结果。
- 两条代码生成路径均发出 LSTP 接触描述，默认定位间隙过零及非负力模式的力截断；仅在接受事件时更新防重复记录，增加 contactEvents 诊断计数。
- 补充 MASS/LSTP 独立事件实验、八路全曲线与驱动阶段配对评估，以及 Amesim 不连续点输出对照和力差定位报告；MASS 新增释放机制仍保留为独立实验。
- 保存局部 probe、context 访问与回退、shadow replay、R288 real skip/typed replay 及阀门数值尾部诊断工具和报告；未证明净收益的实验不启用为生产默认优化。
- 更新原生运行说明和元件建模规范，补充信号边界、输出语义、接触事件和实验依赖回归测试。

验证：五组专项回归共 34 项全部通过；37 个待提交 Python 文件语法检查通过；git diff --cached --check 通过。

tests/manual/verify_context_access_evidence.py

@@ -0,0 +1,56 @@
+"""Negative checks of the evidence validator (not a production reuse guard)."""
+from copy import deepcopy
+import json
+import analyze_context_access as ax
+
+
+def rejected(events):
+    try:
+        ax.analyze_operation(events)
+    except AssertionError:
+        return True
+    return False
+
+
+def main():
+    examples=json.loads((ax.OUT/'jacobian-200.json').read_text(encoding='utf-8'))
+    original=next(x['events'] for x in examples if x['summary']['group']==6)
+    assert ax.analyze_operation(original)['replayExact']
+    results={}
+
+    events=deepcopy(original)
+    index=next(i for i,e in enumerate(events) if e['event']=='write' and e.get('domain')=='pipes' and e.get('field')=='cache->valid')
+    del events[index]
+    results['omitted_equal_value_pipe_valid_store']=rejected(events)
+
+    events=deepcopy(original)
+    event=next(e for e in events if e['event']=='read' and e.get('field')=='s->rho')
+    event['value']='0000000000000000'
+    results['wrong_consumed_rho']=rejected(events)
+
+    events=deepcopy(original)
+    event=next(e for e in events if e['event']=='allocate')
+    event['slot']-=1
+    results['baseline_slot_used_for_shifted_append']=rejected(events)
+
+    events=deepcopy(original)
+    event=next(e for e in events if e['event']=='write' and e.get('field')=='cache->count')
+    event['value']=(13).to_bytes(8,'little').hex()
+    results['restored_baseline_count']=rejected(events)
+
+    events=deepcopy(original)
+    event=next(e for e in events if e['event']=='match')
+    event.update(hit=True,slot=0)
+    results['wrong_first_match']=rejected(events)
+
+    events=deepcopy(original)
+    event=next(e for e in events if e['event']=='valid_test' and e['mask']==8)
+    event['value']=8
+    results['wrong_valid_bit_result']=rejected(events)
+
+    assert all(results.values()), results
+    (ax.OUT/'negative-checks.json').write_text(json.dumps(results,indent=2)+'\n',encoding='utf-8')
+    print(json.dumps(results,indent=2))
+
+
+if __name__=='__main__':main()