Fix issues found by mirror linter

pkg/cfg/config.go

@@ -93,7 +93,7 @@ func readGitconfig(cfg Gitconfig) {
 
 	viper.SetConfigType("env")
 
-	if err := viper.ReadConfig(bytes.NewBuffer([]byte(strings.Join(lines, "\n")))); err != nil {
+	if err := viper.ReadConfig(bytes.NewBufferString(strings.Join(lines, "\n"))); err != nil {
 		// Log error but don't fail - configuration is optional
 		fmt.Fprintf(os.Stderr, "Warning: failed to read git config: %v\n", err)
 	}

pkg/git/repo_test.go

@@ -413,6 +413,7 @@ func TestRemote(t *testing.T) {
 func createTestDirTree(t *testing.T) string {
 	t.Helper()
 	root := test.TempDir(t, "")
+
 	err := os.MkdirAll(filepath.Join(root, "a", "b", "c"), os.ModePerm)
 	if err != nil {
 		t.Fatal(err)

pkg/git/test/helpers.go

@@ -39,7 +39,7 @@ func (r *Repo) writeFile(filename string, content string) {
 	file, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
 	checkFatal(r.t, err)
 
-	_, err = file.Write([]byte(content))
+	_, err = file.WriteString(content)
 	checkFatal(r.t, err)
 }
 

pkg/run/run.go

@@ -34,6 +34,7 @@ type Cmd struct {
 // Git creates a git command with given arguments.
 func Git(args ...string) *Cmd {
 	ctx := context.Background()
+
 	return &Cmd{
 		cmd:  exec.CommandContext(ctx, "git", args...),
 		args: strings.Join(args, " "),