AGENTS.md is the part that should not churn: the settled decisions with their
reasons, the invariants that hold the design together, the working rules, and
the security-sensitive areas that have been wrong before. A new agent should
read it and STATUS.md and know what not to re-litigate.
Deliberately excluded: anything about how to search, read or patch. Those are
being automated per round, and writing advice about them into the repo would
rot. What is here instead is project-specific and cannot be automated away —
for example that a PTR suffix must match on a label boundary, that a truncated
answer must never be cached, and that the UDP read deadline has to be reset every
iteration or the loop spins.
The working rules are the part worth arguing for. Never leave the tree red,
because nobody can detect the budget running out: three of five subagents left
broken files, and each cost a round to discover. Report honestly, and when a test
fails, decide first whether the test, the implementation or the specification is
wrong — all three happen here, and the decision belongs in the commit message.
STATUS.md now records a fully green tree: nine packages with suites, all passing
under -race. The plan starts with internal/engine, which is the largest
uncovered surface and the one every packet goes through.
