Implement robust and type-safe configuration handling to avoid fragile hardcoding and improve maintainability. Key guidelines: 1. Use type-safe structures for passing configuration between processes instead of raw strings 2. Avoid hardcoding environment paths or configuration values 3. Use environment variables through a centralized configuration system 4. Validate configuration values at startup Example of improved configuration handling: ```rust // Instead of this: let docs = env::args_os().nth(1).expect("doc path should be first argument"); let docs = env::current_dir().unwrap().join(docs); // Do this: #[derive(Parser)] struct Config { docs: PathBuf, #[clap(long)] link_targets_dir: Vec, } let config = Config::parse(); let docs = config.docs.canonicalize()?; ``` This approach: - Makes configuration requirements explicit - Provides type safety - Centralizes configuration handling - Makes testing and validation easier - Reduces fragility from hardcoded values