Write rules as operational constraints: with repo rules enabled

Tip: Rules are not a style essay

Say what the agent must never do: no seed, keep published_at filters, no JS build. Put always-on constraints in .cursor/rules or AGENTS.md.

---
description: lexprog invariants
globs: src/**/*.rs
---
Never run cargo run --bin seed.

Gotcha: A rule that restates Rust book (with repo rules enabled)

The model already knows Rust. Spend tokens on this repo's footguns. A 20k rule file will bury the one footgun; keep rules short.

# What is ownership?

Source: https://docs.cursor.com/context/rules