Fourth style family (LibreOffice's Listenformatvorlagen): per-level model in
styles/listStyles.ts, five probed LO built-ins, listStyleName on the outermost
list, one effective-level resolver shared by the decoration walk and the export.
ODF writes the full named text:list-style into styles.xml and repoints
unoverridden lists at it (overrides keep the resolved automatic clone);
import maps named list styles back to the attr + registry, attr-free.
Probed: LO keeps the named reference and display-name across a re-save.