W16: close CRITICAL/HIGH findings, integrate metadata gate, complete audit summaries (W16.1-W16.6)

- W16.1 (曹武): F-11.7-1 CLOSED — confirmed W12.4 fix, corrupt binary eliminated
- W16.2 (孙宇): F-11.1-1 FIXED — context_plugin.cpp try/catch on set_max_tokens + on_shutdown
- W16.3 (陈风): F-11.1-2 CLOSED — confirmed W12.1 fix, strdup OOM protection already in place
- W16.4 (胡桐): Integrate check_agents_metadata into refresh_status.py as pre-gate (error→exit 1)
- W16.5 (周岩): Add Findings Summary to W13.3 network audit, register 3 findings
- W16.6 (赵码): Add Findings Summary to W13.1+W13.2 AI audits, register 8 findings (4 already W14-fixed)

Build 0 error, ctest 4/4 pass, metadata check 0 error 0 warning.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

agents/audits/W13.3-network-audit.md

@@ -164,3 +164,13 @@ HttpClientCtx() {
 | **综合** | **C** |
 
 **总评**: RAII、堆纪律、字符串生命周期、并发安全均高质量。但 TLS 证书验证完全禁用 (F) 是致命安全缺陷，DNS 无超时可无限 hang。两个问题 (TLS + DNS) 使该插件在任何生产环境中不可用。修复后预期可达 A 级。
+
+---
+
+## Findings Summary
+
+| ID | Severity | Title |
+|----|----------|-------|
+| F-13.3-1 | CRITICAL | TLS 证书验证完全禁用：`set_verify_mode(ssl::verify_peer)` 未调用，默认 `verify_none` 接受任何证书，无 hostname 验证 (L87-93) |
+| F-13.3-2 | HIGH | DNS 解析无超时：`resolver.resolve(host, port)` 同步调用，socket 未创建无法设超时，DNS 无响应则线程永久阻塞 (L142) |
+| F-13.3-3 | MEDIUM | 异常处理缺 `catch(...)` 兜底：仅捕获 `std::exception&`，非标准异常 (SEH/自定义) 穿越 C ABI → `std::terminate()` (L251) |