release(v4.7.3): bump framework and eight skills to 4.7.3 in lockstep; archive PR #37 merge-side reviews

Issue #36: delegated prompts travel by file, a delegation that fails ends
the loop with rc 1. VERSIONS.md carries the entry; the merge-side reports
(round 1 @59be1c8 and round 2 @708262a with identity sidecars, base
59be1c8 -> head 708262a, evidence review-tree) are archived under
.agents/reports/<session>/.

Co-Authored-By: Claude Fable 5.1 <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: v4.7.2](https://img.shields.io/badge/version-v4.7.2-blue.svg)](VERSIONS.md)
+[![Version: v4.7.3](https://img.shields.io/badge/version-v4.7.3-blue.svg)](VERSIONS.md)
 
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