Authoring .pr-agent repo policy rules

Overview

One structured pass → inventory gaps → emit new one-gotcha .mdc files under .pr-agent/ (leading dot). That directory is the only durable preference memory the PR Agent loads (REPO_POLICY_DIRNAME in src/settings/reviewConstants.ts, ADR 0025).

Core principle: A rule earns its slot only if a careful reviewer of this repo would miss the bug without it.

Iron Law

NO GENERIC ADVICE. NO BLOBS. NO WRONG DIRECTORY. NO DUPLICATES.

No exceptions: