Rust Ecosystem

Part of src/cmds/ — see also docs/contributing/TECHNICAL.md

Specifics

cargo_cmd.rs uses restore_double_dash() fix: Clap strips -- but cargo needs it for test flags (e.g., cargo test -- --nocapture)
runner.rs is a generic two-mode runner (err = stderr only, test = failures only) used as fallback for commands without a dedicated filter. It executes argv directly by default; --shell <name> '<script>' is the explicit escape hatch for shell syntax.
runner.rs is also referenced by other modules outside this directory as a generic command executor