fix: preserve ZIP entry timestamps

chfs-ng/internal/api/server.go

@@ -828,7 +828,9 @@ func (s *Server) downloadDir(w http.ResponseWriter, r *http.Request) {
 				}
 				continue
 			}
-			h, err := zw.Create(rel)
+			header := &zip.FileHeader{Name: rel, Method: zip.Deflate}
+			header.SetModTime(item.ModTime())
+			h, err := zw.CreateHeader(header)
 			if err != nil {
 				return err
 			}