Claude Code runs gstack's hook shims through /bin/sh; a shim that does not
parse exits 2, which for a PreToolUse hook blocks the tool call in every
session until someone finds the file. Before any hook registration is
healed or written, setup now runs bash -n on each registered shim and a Bun
parse of its TypeScript entry, and stops with the file, line and fix. A
lean rewrite of the PR's idea (one gate block plus a test that runs it).
Co-authored-by: BenjaminDSmithy <BenjaminDSmithy@users.noreply.github.com>
