// Package launcher orchestrates the application lifecycle.
//
// A Launcher manages infrastructure components through three ordered phases:
//
//  1. OnInit — all components initialize in registration order
//  2. BeforeStart hooks — dependency injection wiring runs
//  3. OnStart — all components start in registration order
//
// On shutdown (OS signal or programmatic Shutdown call), OnStop is called for
// every component in reverse registration order, ensuring dependents stop
// before their dependencies.
//
// Usage:
//
//	logger := logz.New(logz.Options{JSON: true})
//	lc := launcher.New(logger)
//
//	lc.Append(db, cache, server)
//	lc.BeforeStart(func() error {
//	    return server.RegisterRoutes(db, cache)
//	})
//
//	if err := lc.Run(); err != nil {
//	    logger.Error("launcher failed", err)
//	    os.Exit(1)
//	}
package launcher