rust-conventions

- Rust 2024 edition, `cargo fmt` + `clippy -D warnings`, zero warnings policy. - `Result<T, E>` with a derive-based error crate (e.g., thiserror) for library errors, a context-adding error crate (e.g., anyhow) for applications. `?` for propagation — never `.unwrap()` in library code. - Minimize `unsafe` — every block needs `// SAFETY:` comment explaining invariants. - Prefer `&str` over `String` in params, `Cow<'_, str>` for conditional ownership, `Arc` for shared ownership. - `impl Trait` in argument position for static dispatch, `dyn Trait` for dynamic dispatch when heterogeneous collections needed. - Small, focused modules. Use `pub(crate)` for internal visibility. Workspace inheritance for multi-crate repos. - `#[cfg(test)]` for unit tests, `tests/` for integration, a coverage tool (e.g., cargo-llvm-cov) for coverage. - Benchmarking: a statistical benchmark harness (e.g., criterion) for microbenchmarks, profile with a flamegraph tool (e.g., cargo flamegraph). - Async: `tokio` runtime, `'static + Send + Sync` bounds, `tokio::spawn` for concurrency. - Security: `cargo audit` for CVE scanning, `cargo deny` for license and advisory policies. - Dependencies: pin versions, commit `Cargo.lock`, prefer well-maintained crates. - Structured logging (spans and events, e.g., the `tracing` crate) — not `println!`. - API naming: follow `as_`/`to_`/`into_` conventions for conversions, `iter()`/`iter_mut()`/`into_iter()` for iterators. Getters are `field()` not `get_field()`. See [Rust A...