-`New(logger logz.Logger, opts ...Options) Launcher` — constructs a `Launcher`; no package-level singletons or global state; variadic opts apply the first element if provided
-`Launcher.Append` — registers one or more components in order; startup proceeds in registration order, shutdown in reverse
-`Launcher.BeforeStart` — registers hooks that run after all `OnInit` calls complete and before any `OnStart` call; correct place for dependency injection wiring
-`Launcher.Run() error` — executes the full lifecycle (OnInit → BeforeStart hooks → OnStart → wait → reverse-order OnStop); blocks until `SIGINT`, `SIGTERM`, or `Shutdown` is called
-`Launcher.Shutdown(ctx context.Context) error` — triggers a graceful shutdown programmatically and waits for `Run` to return; idempotent via `sync.Once`, safe to call from multiple goroutines; ctx controls the caller-side wait timeout only
- OS signal handling for `SIGINT` and `SIGTERM` built into `Run` with automatic `signal.Stop` cleanup on return
- Per-component independent stop timeout: each component's `OnStop` runs in its own goroutine and is abandoned (with an error log) if it exceeds `ComponentStopTimeout`
### Design Notes
- The three-phase lifecycle (OnInit / BeforeStart / OnStart) cleanly separates resource allocation from dependency wiring from service activation, ensuring no component begins serving traffic before all its dependencies are fully initialized.
- Shutdown runs in strict reverse registration order with a per-component independent timeout, so a stalled component cannot block others from stopping; worst-case shutdown time is `n × ComponentStopTimeout`.
-`Shutdown` closes a channel via `sync.Once` rather than using a mutex or flag, making it genuinely safe to call concurrently from an OS signal handler and a test teardown racing against each other.
