org-ops dispatched a work order (20260814T144553Z) from an /insights sweep
of 160 sessions: a real STATE.md drifted to 155-156 lines before anyone
noticed, and one trim pass on it increased the line count instead of
shrinking it. Prose alone doesn't enforce.
org-ops proposed a PostToolUse hook. Checked against the official hooks
docs first: PostToolUse fires after the tool has already written the file
and cannot block it (confirmed "Can block? No"), only nag afterward. Built
it as PreToolUse instead, the only event that can deny the call before the
file lands.
pre-state-line-guard.mjs denies (stderr + exit 2, matching llm-security's
pre-write-pathguard.mjs) a Write or Edit on any STATE.md whose projected
result exceeds 60 lines. Write projects from the call's own content; Edit
projects from the current on-disk file with old_string replaced by
new_string, honoring replace_all (every occurrence) vs the default (first
occurrence only) the same way the real Edit tool does. Anything the hook
can't project confidently (missing file, old_string not found) is left to
the real tool.
state-line-guard-selftest.sh: 16 checks, including a replace_all fixture
that a first-occurrence-only projection would wrongly allow. Wired into
hooks/hooks.json as PreToolUse on Write|Edit. Version 0.22.0 -> 0.23.0.
Suite total: 191 + 152 + 69 + 16 = 428.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0186kZGKddxfA9N84HqMLbb2
