Fix undo last reject for moved or renamed files

[jsgrrchg]

Summary

Undo last reject does not restore agent changes when the rejected change moved or renamed a file.

Problem

After rejecting a move/rename, the file is back at its original path, but undoLastReject validates the hash at the new path (snapshot.path). Since that path no longer exists, the hash is null and the restore is skipped.

Expected behavior

Undoing the reject should reapply the agent change and move/rename the file again.