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.md

@@ -2,7 +2,7 @@
 
 An advanced, high-reliability **Multi-Agent Orchestration & Messaging Backplane** framework built on Herdr and MQTT. It is designed to coordinate, isolate, and audit long-running agent tasks (such as code generation, refactoring, and security reviews) across multiple LLM backend clients (`claude`, `agy`, `hermes`, `grok`, `opencode`, `codex`).
 
-[![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)
 
 ---