build spotify-to-navidrome migrator with recovery flow

internal/report/report.go

@@ -0,0 +1,24 @@
+package report
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"navimigrate/internal/model"
+)
+
+func Write(path string, rep model.TransferReport) error {
+	f, err := os.Create(path)
+	if err != nil {
+		return fmt.Errorf("create report file: %w", err)
+	}
+	defer f.Close()
+
+	enc := json.NewEncoder(f)
+	enc.SetIndent("", "  ")
+	if err := enc.Encode(rep); err != nil {
+		return fmt.Errorf("encode report: %w", err)
+	}
+	return nil
+}