Add safety check and state tracking in File's Move method

internal/pkg/file.go

@@ -2,6 +2,7 @@ package pkg
 
 import (
 	"crypto/rand"
+	"fmt"
 	"os"
 	"path/filepath"
 	"time"
@@ -47,5 +48,14 @@ func (f *File) Remove() error {
 }
 
 func (f *File) Move(path string) error {
-	return os.Rename(f.filepath, path)
+	if f.isMoved {
+		return fmt.Errorf("file already moved")
+	}
+
+	if err := os.Rename(f.filepath, path); err != nil {
+		return err
+	}
+
+	f.isMoved = true
+	return nil
 }