rust-engineeringlisted

# Rust Engineering Write Rust that makes architecture, ownership, failure, concurrency, safety, and performance reasoning understandable to the next maintainer. Prefer repository evidence and semantic types over universal thresholds, clever compression, or speculative optimization. ## Establish the Contract 1. Read scoped instructions, `Cargo.toml`, workspace configuration, CI, lint policy, formatting configuration, relevant ADRs, public APIs, nearby tests, and representative call sites. Discover the edition, MSRV, supported targets, feature combinations, async runtime, and repository-native commands. 2. State the changed behavior and boundaries: inputs, outputs, ownership, mutation, expected errors, possible panics, cancellation, ordering, concurrency, resource limits, and any safety invariant. Do not invent a stronger MSRV, lint set, runtime, crate, or performance target. 3. Read [Ownership and API design](references/ownership-and-api-design.md) for borrowing, newtypes, parsing, trait boundaries, and abstraction choices. 4. Read [Architecture and boundaries](references/architecture-and-boundaries.md) when the task changes crate/module structure, public interfaces, services, domain types, persistence, async boundaries, or project organization. 5. Read [Naming and readability](references/naming-and-readability.md) for semantic names, Unicode-safe text handling, constants, comments, and maintainable control flow. 6. Read [Errors and concurre