Prek — Pre-commit Formatter Setup

prek is a fast, Rust-native drop-in alternative to pre-commit. It reads prek.toml and runs formatters automatically on staged files at commit time.

Formatters — all use 4 spaces, no tabs, line-length 120:

• Python: ruff-check --fix + ruff-format (via astral-sh/ruff-pre-commit)
• SQL: uv run sqlfmt (local hook)
• TypeScript/JS: bunx --bun @biomejs/biome check --write (local hook, also lints and organizes imports)
• YAML: builtin check-yaml (if .yaml/.yml files present)
• File-size guard: scripts/check_files.py (local hook, always included) — blocks commits containing files over a per-extension line-count limit, and (for .sql) forbidden join patterns. BMS convention, seen in mdmapp and OneSales.

Step 0: Ensure prek is installed