v3.10.1: Codex Unix hook JSON compatibility

What changed:

• Codex shell-backed hooks on Linux and macOS now use the shared event adapter. This fixes the invalid JSON failures reported for SessionStart and UserPromptSubmit in issue #220 and covers the same path for PreCompact.
• The tracked npm package source and sync manifest now match the 20-script tarball already published for v3.10.0, so the release tag, source tree, and package provenance are aligned.
• Installation docs now distinguish direct npm vendoring from Pi's automatically wired route. The npm listing still includes the Pi extension.
• The README now uses committed terminal-style SVGs for the /clear comparison and labels its statistics table.
• The version bumper now reports absent gitignored ClawHub staging without failing in a fresh clone, while still updating and validating that stage whenever it exists.

Thanks: @mfehlhaber for reporting issue #220.