Crate cbh_cli 

Implementation crate for cargo-bench-history; do not depend on this directly.

The argument-parsing surface: the clap-derived [Cli] that turns argv into the typed Command model, and the [EarlyExit] value that carries a help listing or a parse error out to the process entry point. Split out of the cargo-bench-history shell so the wide clap surface is isolated for mutation testing.

Every item is re-exported flat from the crate root, so consumers write cbh_cli::Cli rather than reaching into a submodule.