W23: close mailroom metadata and network validation tests

- Refresh agents STATUS to W22.6 and exclude mailroom from metadata scans
- Add mailroom dispatch checklist and defensive rules
- Register F-23.D-1 and tag network input validation defense-in-depth
- Update network plugin tests for header length limits
- Fix LSP test metadata and remove orphan anthropic_internal.hpp

Verification:
- cmake --build build --config Release: 0 error, 0 warning
- ctest --test-dir build --output-on-failure: 10/10 passed
- ctest --test-dir build -R dstalk_smoke_test --output-on-failure: passed
- python scripts/check_agents_metadata.py --strict: passed

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

agents/PROMPT_TEMPLATE.md

@@ -186,7 +186,7 @@ cmake --build build --config Release && ctest --test-dir build -C Release
 
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-## CEO 派活前 4 步检查
+## CEO 派活前 5 步检查
 
 派活前逐项确认，缺一不可：
 
@@ -196,6 +196,7 @@ cmake --build build --config Release && ctest --test-dir build -C Release
 | 2 | **找前序 Wave 产出** | 从 `agents/*/profile.md` 的 performance_log 追溯与本任务关联的之前 Wave 的产出文件 | `前序成果` |
 | 3 | **设定任务范围三档** | 把需求拆成"必做/可做/不做"，不做 = 硬边界 | `任务范围` |
 | 4 | **统一字数上限** | 固定 250 字，不再按任务调整 | `字数上限` |
+| 5 | **扫候选执行者 inbox** | 查看 `agents/mailroom/inbox/<agent-id>/` 是否有 pending handoff / blocker；有阻塞先处理阻塞 | `前序成果` / `禁忌` |
 
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