User insight: hardlink breakage only happens at deploy time (scp file
replacement / git checkout-merge), so detection must be welded INTO the
deploy pipeline, not left to daily audit.
Three automatic layers, no reliance on discipline:
1. systemd path watcher (profile-scripts-sync.path): watches
deploy/profile-scripts/ directory, auto-fires sync_profile_scripts.sh
on any change. Verified: fires within 4s of file replacement, logs to
gateway/logs/link_sync.log (runs as hmo user)
2. git hooks (.git/hooks/post-merge + post-checkout on 246 repo):
auto re-link after git operations
3. Manual fallback: sync_profile_scripts.sh (now self-logging)
dev-spec red line #6 updated: SSOT rule now documents the three layers
and states breakage only happens at deploy time.