// Package worker provides a concurrent goroutine pool with lifecycle management.
//
// # Lifecycle
//
// The component follows the lifecycle.Component contract:
//   - OnInit: logs pool configuration; no goroutines are started.
//   - OnStart: launches PoolSize goroutines that consume from the task queue.
//   - OnStop: closes the task queue, cancels the pool context, then waits up to
//     ShutdownTimeout for all goroutines to finish. Returns nil regardless of
//     whether the drain completed before the deadline.
//
// Register with the launcher before starting:
//
//	pool := worker.New(logger, cfg)
//	launcher.Register(pool)
//
// # Dispatching Tasks
//
// Dispatch is non-blocking. It returns false immediately when the buffer is full.
// A false return means the task was dropped — the caller is responsible for
// retry or overflow handling.
//
//	ok := pool.Dispatch(func(ctx context.Context) error {
//	    return sendEmail(ctx, msg)
//	})
//	if !ok {
//	    // queue was full; handle backpressure
//	}
//
// # Interface Segregation
//
// Inject Provider into callers that only dispatch work.
// Pass Component to the launcher registration site.
//
// # Configuration
//
//	EINHERJAR_WORKER_POOL_SIZE        — number of concurrent goroutines; default 5
//	EINHERJAR_WORKER_BUFFER_SIZE      — task queue capacity; default 100
//	EINHERJAR_WORKER_TASK_TIMEOUT     — per-task deadline (0 = no deadline); default 0s
//	EINHERJAR_WORKER_SHUTDOWN_TIMEOUT — OnStop drain deadline; default 30s
package worker