Update changelog and MCPB installer docs

[Mr-Lucky]

Summary

Update the changelog, MCPB installer behavior, Hermes documentation, and related test coverage for the recent PR #106/#107 work.

Type

• Bug fix
• New feature / detection rule
• Refactoring
• Documentation

Testing

• npm run build passes
• npm test passes (384 tests)
• Manually tested the change

Related Issues

Closes #

[github-actions]

AgentGuard PR Review

I found one actionable issue in the patch.

1. severity: high — src/installers.ts / Hermes native plugin config merge
   What can go wrong: enableHermesNativePlugin() now writes ~/.hermes/config.yaml by parsing and rewriting it with a custom line-based parser. This parser is not YAML-safe and can silently drop or mis-handle existing config structure/comments, especially for nested blocks or values that span multiple lines. In the worst case, it can corrupt the Hermes config and break agent startup, or partially rewrite the wrong section while still reporting success.
   Fix suggestion: Avoid hand-rolling YAML edits. Parse and emit with a real YAML library, or use Hermes’ own plugin management commands/API (hermes plugins enable agentguard) and keep the installer limited to copying files. If config editing must stay, add validation that the rewritten file parses successfully and preserve unrelated content with a YAML AST-based update.