release(v4.9.0): Issue #50 / #55 - archive the review reports and bump the lockstep version

Merge review on macOS (--review-only loops, --all-reviewer): round 1 at
320aa9f 4/4 NOT PASS, round 2 codex F1 (a claimed dry-run job holds its
session), round 3 4/4 PASS (discarded: the worktree changed mid-review),
round 4 at 21f0c12 claude/agy/grok PASS with codex interrupted by a stream
disconnect, round 5 codex PASS. Full suite at 21f0c12 on macOS / Python
3.9 / bash 3.2 / herdr 0.9.3: 1860 passed / 0 failed / 38 skipped; no new
entries in ~/.claude/projects.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff

README.ko.md

@@ -2,7 +2,7 @@
 
 Herdr와 MQTT 브로커를 기반으로 구축된 고신뢰성 **다중 에이전트 오케스트레이션 및 메시징 백플레인** 프레임워크입니다. `claude`, `agy`, `hermes`, `grok`, `opencode`, `codex` 등 다중 LLM 백엔드 에이전트 전반에 걸쳐 장시간 수행되는 작업(코드 생성, 리팩토링, 보안 검토 등)을 조정, 격리 및 감사할 수 있도록 설계되었습니다.
 
-[![Version: v4.8.9](https://img.shields.io/badge/version-v4.8.9-blue.svg)](VERSIONS.md)
+[![Version: v4.9.0](https://img.shields.io/badge/version-v4.9.0-blue.svg)](VERSIONS.md)
 
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