rsenv: Unified development environment manager

This library provides the core functionality for rsenv, consolidating:

• Hierarchical environment variable management (rsenv v1)
• File guarding with symlinks (confguard)
• File swap-in/out (rplc)

Architecture

The crate follows clean architecture with layered error types:

• domain: Core entities and business rules
• application: Services orchestrating domain logic
• infrastructure: I/O implementations and DI container
• cli: Command-line interface

Example

use rsenv::config::Settings;
use rsenv::infrastructure::di::ServiceContainer;

let settings = Settings::load(None).unwrap();
let container = ServiceContainer::new(settings);