CLI Domain Layer 3: Domain Constraints Domain Constraints → Design Implications | Domain Rule | Design Constraint | Rust Implication | |-------------|-------------------|------------------| | User ergonomics | Clear help, errors | clap derive macros | | Config precedence | CLI env file | Layered config loading | | Exit codes | Non-zero on error | Proper Result handling | | Stdout/stderr | Data vs errors | eprintln! for errors | | Interruptible | Handle Ctrl+C | Signal handling | --- Critical Constraints User Communication Configuration Priority Exit Codes --- Trace Down ↓ From constraints to…