Code quality setup

Formatter automation model

The repository formatter runs across three layers (obligation: engineering-standards):

1. Editor/agent edit flows format in write mode immediately after creating or modifying formatter-managed files.
2. Pre-commit hooks format changed files in write mode and stage the result.
3. CI runs formatter checks in check-only mode and fails on drift, without writing, committing, or otherwise mutating the repo.

GitHub Actions runtime currency

Keeping JavaScript actions on GitHub's current GA Node major (obligation: engineering-standards) uses this migration procedure: