Rust Best Practices Unified Rust guidelines covering coding style, ownership, error handling, async patterns, traits, testing, performance, linting, and documentation. Apply when writing or reviewing Rust code. When to Apply - Writing new Rust code or designing APIs - Reviewing or refactoring existing Rust code - Implementing async systems with Tokio - Designing error hierarchies with thiserror/anyhow - Choosing between borrowing, cloning, or ownership transfer - Setting up tests, benchmarks, or snapshot testing - Configuring clippy lints and workspace settings - Optimizing Rust code for perf…