Module entrypoint 

The binary target’s entry point. It lives here rather than in src/main.rs so the binary root stays declaration-only: Rust requires a main in that file, and a fn main with a body is a unit-gate subject whose own #[cfg(test)] module the unit suite would have to run. A re-export carries no function, so the gates read main.rs as declarations and the logic sits here, under test.

Functions

main

Run the CLI over the process arguments and map the outcome onto an exit code.