scripts/ci/check_agents_md_size.py (in scripts/check and lint.yml): root <= 12k, every
AGENTS.md plus its ancestors <= 30k (the joined root->cwd block on a 128k window, minus
the per-file labels), every area file <= _MAX_HINT_CHARS read from the source so the two
cannot drift. On origin/main it reports the root and all 11 root-to-area chains over.