Add OpenTelemetry tracing and log correlation

cmd/gl/main.go

@@ -29,6 +29,8 @@ func main() {
 		slog.Error("load configuration", "error", err)
 		os.Exit(1)
 	}
+	shutdownTelemetry := observability.Setup(context.Background(), cfg.Telemetry, "gl", cfg.Environment)
+	defer shutdownTelemetry(context.Background())
 
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
 	defer stop()