fix: lazysecrets list keeps each entry on one line, errors to their first

internal/listing/listing_test.go

@@ -211,3 +211,15 @@ func TestListKinds(t *testing.T) {
 		t.Error("a list that failed wasn't listed")
 	}
 }
+
+func TestErrorsAreOneLine(t *testing.T) {
+	for in, want := range map[string]string{
+		"403 Forbidden: Caller is not authorized\nCaller: appid=x;oid=y\nVault: kv;location=z": "403 Forbidden: Caller is not authorized",
+		"\n  timeout\tafter 30s\n": "timeout after 30s",
+		"":                         "unreadable",
+	} {
+		if got := firstLine(in); got != want {
+			t.Errorf("firstLine(%q) = %q, want %q", in, got, want)
+		}
+	}
+}