The remaining slash commands already existed in the REPL path, so this change
focuses on wiring the active CLI parser and runtime to expose them safely.
`--version` now exits through a local reporting path, and `--allowedTools`
constrains both advertised and executable tools without changing the underlying
command surface.
Constraint: The active CLI parser lives in main.rs, so a full parser unification would be broader than requested
Constraint: --version must not require API credentials or construct the API client
Rejected: Migrate the binary to the clap parser in args.rs | too large for a parity patch
Rejected: Enforce allowed tools only at request construction time | execution-time mismatch risk
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Keep local-only flags like --version on pre-runtime codepaths and mirror tool allowlists in both definition and execution paths
Tested: cargo fmt; cargo clippy --workspace --all-targets -- -D warnings; cargo test; cargo run -q -p rusty-claude-cli -- --version; cargo run -q -p rusty-claude-cli -- --help
Not-tested: Interactive live API conversation with restricted tool allowlists