603872ff76
Repo-level instructions so GitHub Copilot follows the LOCKED naming rules (lowercase concatenated DB columns, allowed-acronym list, banned shorthand), the ASCII-only style policy, and the plugin/migration/contract architecture. Without this Copilot suggests snake_case columns, em-dashes, and db.create_all(), which the naming hook and CI then reject. Distilled from CONTRIBUTING.md; that file stays the authority.