Centralize deterministic JSON file writing

internal/trim/run.go

@@ -8,6 +8,7 @@ import (
 	"sort"
 
 	"gitea.maximumdirect.net/eric/seriatim/internal/config"
+	"gitea.maximumdirect.net/eric/seriatim/internal/jsonfile"
 	"gitea.maximumdirect.net/eric/seriatim/internal/report"
 )
 
@@ -85,7 +86,7 @@ func Run(ctx context.Context, cfg config.TrimConfig) error {
 		return fmt.Errorf("validate trimmed output: %w", err)
 	}
 
-	if err := writeOutputJSON(cfg.OutputFile, outputArtifact.Value()); err != nil {
+	if err := jsonfile.Write(cfg.OutputFile, outputArtifact.Value()); err != nil {
 		return err
 	}
 
@@ -137,18 +138,6 @@ func Run(ctx context.Context, cfg config.TrimConfig) error {
 	return nil
 }
 
-func writeOutputJSON(path string, value any) error {
-	file, err := os.Create(path)
-	if err != nil {
-		return err
-	}
-	defer file.Close()
-
-	enc := json.NewEncoder(file)
-	enc.SetIndent("", "  ")
-	return enc.Encode(value)
-}
-
 func orderedIDMapping(mapping map[int]int) []idMapping {
 	keys := make([]int, 0, len(mapping))
 	for oldID := range mapping {