[claybridges]

The dev binary went stale whenever main moved, and post-merge can't catch it: main is often detached, and finished work lands with git branch -f main. A reference-transaction hook fires on every ref update.

• Hook is thin zsh; it only acts on a committed refs/heads/main update and always exits 0
• Rebuild is scripts/rebuildDevBinary.go: builds from git archive main, so the active worktree doesn't matter, then installs atomically
• Runs detached, so git never waits; concurrent triggers collapse into one extra rebuild
• Opt in with go tool task main-hook:install. It symlinks the hook, so scripts/ changes take effect without re-installing
• go tool task main-hook:uninstall removes it, and so does go tool task use-brew
• Scripts are Go (//usr/bin/env go run first line, //go:build ignore), outside the normal build

🤖 Generated with Claude Code

[claybridges]

Reviewed.