// Package app orchestrates modular application setup and teardown.
//
// Register subsystems as [Module] values, attach them to a [Lifecycle], and call
// [Lifecycle.Setup] or [Lifecycle.Require] to initialize resources in dependency
// order. Always call [Lifecycle.Teardown] (typically via defer) to release
// resources in reverse setup order.
//
// Module authors (dbx, applog, migrate, etc.) and main/cmd packages both import
// app. Use [Lifecycle.Context] to propagate the lifecycle through context.Context
// for CLI commands via [gitea.auvem.com/go-toolkit/appcli].
//
// # Concepts
//
//   - [Module] — named unit with optional Setup, Teardown, and Depends
//   - [Lifecycle] — registry and orchestrator for modules
//   - Setup order — dependencies first; autoload resolves Depends when enabled
//   - Require — lazy/conditional setup (common in CLI subcommands)
//
// # API overview
//
// Lifecycle — [NewLifecycle], [Lifecycle.Setup], [Lifecycle.Teardown],
// [Lifecycle.Require], [Lifecycle.RequireWithOpts], [Lifecycle.GetModule],
// [Lifecycle.Context], [LifecycleFromContext]
//
// Module — [NewModule], [Module.Lifecycle], [Module.Logger], [Module.Loaded]
package app