CVE-2026-70463: parse "auth users" with conf_strtok so a leading comma splits
on commas alone, restoring "@Group Name" deny/:ro rules that whitespace
tokenisation had silently discarded (authorization bypass)
CVE-2026-53786: strip the module_dir prefix before checking a client-supplied
--filter merge file against daemon_filter_list, so module filter rules can no
longer be bypassed
CVE-2026-70459: reject a non-directory "." / "/." transfer-root file-list
entry and require dir_flist to hold an entry before trusting parent_ndx 0,
fixing the wild-pointer read that crashed the daemon child
CVE-2026-53789: force implied-parent directories non-content on the receiver,
including the synthetic transfer root and the legacy protocol < 30
XMIT_TOP_DIR path, so a malicious sender cannot widen --delete scope