refactor(ecstore): scope dead code allowances (#4098)

crates/ecstore/src/data_movement/mod.rs

@@ -12,6 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// #730: data-movement migration keeps staged cleanup helpers until copy paths converge.
+#![allow(dead_code)]
+
 pub(crate) mod backpressure;
 
 use crate::error::{Error, Result, is_err_data_movement_overwrite, is_err_object_not_found, is_err_version_not_found};