//! Infrastructure Layer (DDD)
//!
//! This module contains infrastructure concerns including low-level command execution,
//! external tool adapters, and repository-like implementations. The infrastructure layer
//! provides technical capabilities and delivery mechanisms for the application layer.
//!
//! ## Components
//!
//! - `templating` - Template rendering and delivery mechanisms for deployment tools
//! - `ansible` - Ansible template generation and project structure
//! - `docker_compose` - Docker Compose template generation
//! - `tofu` - `OpenTofu` template generation and project structure
//! - `tracker` - Torrust Tracker configuration templates
//! - `remote_actions` - SSH-based operations executed inside VMs
//! - `external_validators` - E2E validation from outside VMs (HTTP health checks)
//! - `persistence` - Persistence infrastructure (repositories, file locking, storage)
//! - `trace` - Trace file generation for error analysis
//! - `schema` - JSON Schema generation from Rust types
//! - `cli_docs` - CLI JSON documentation generation from Clap structures
//! - `dns` - DNS resolution for domain validation