#File structure

Assign code to the narrowest capability that owns it.

#Crates and modules

#Why

Domain logic should not need a binary's terminal presentation to inspect a value.

#Rules

• MUST separate reusable library behavior from binary presentation and resource adapters. [review]

• MUST use Cargo workspaces when the repository owns multiple related crates. [review]

• MUST keep lib.rs and main.rs entrypoints small and deliberate. [review]

• MUST expose only the supported public surface; prefer private or pub(crate) items internally. [review]

• MUST name modules for domain responsibilities rather than catch-all helpers. [review]

• MUST use explicit imports and re-exports rather than wildcard API surfaces. [review]

• MUST keep tests beside their capability or in the owning crate's integration tests. [review]

[review]

Cargo and the compiler validate module boundaries. Review checks ownership, public visibility, and entrypoint scope.

#Enforcement

Cargo and the compiler validate module boundaries. Review checks ownership, public visibility, and entrypoint scope.