fix: correct n8n sandbox escape entry points and key operation semantics(#6)

[Dametime-0]

修正 n8n 沙箱逃逸样本的入口点和关键操作语义

• entry-00099 (CVE-2026-1470): move entry_point from @post decorator to runManually handler method body; rewrite trace to show exploit flow (WithStatement → PrototypeSanitizer gap → RCE)
• entry-00100 (CVE-2026-1470): move critical_operation from sanitizer function (defense) to PrototypeSanitizer (missing identifier shadowing check); rebuild trace to show __sanitize shadowing bypass path
• entry-00511 (CVE-2026-25049): verify accurate critical_operation at findExtendedFunction native fallback; rewrite desc to reflect extend() functionName unvalidated property access chain
• entry-00512 (CVE-2026-25049): verify accurate critical_operation at reset.ts __sanitize plain assignment; expand desc to show VM-side writable sanitizer bypass
• All 4 entries: verify 0 → 1, desc fields rewritten with exploit semantics, line numbers verified against source at vulnerable commits

修正了自动标注流水线的三个系统性错误：

1. 装饰器当作入口点 —— @post 是静态元数据而非可执行代码
2. 防御机制标注为缺陷点 —— sanitizer/PrototypeSanitizer 是沙箱防护而非漏洞利用点
3. trace 描述的是沙箱安装流程而非攻击绕过链路