fix(store): close pool on failed Ping; add ListEndpoints test

internal/store/store.go

@@ -16,6 +16,7 @@ func New(ctx context.Context, dsn string) (*Store, error) {
 		return nil, err
 	}
 	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
 		return nil, err
 	}
 	return &Store{Pool: pool}, nil