prepare for symclone.

From now on, _src.posix will be the single source of truth.
And _home(.*) will symlink into it.

_src.posix/private_dot_config/sz.env/PATH_zz_cleanup.env

@@ -0,0 +1,15 @@
+#!/usr/bin/env -S sh -c 'echo "Not a user script. source(aka .) only"'
+
+# Remove duplicates from PATH
+OLDPATH="$PATH"; NEWPATH=""; colon=""
+while [ "${OLDPATH#*:}" != "$OLDPATH" ]; do
+    entry="${OLDPATH%%:*}"; search=":${OLDPATH#*:}:"
+    [ "${search#*:"$entry":}" = "$search" ] && [[ -d $entry ]] && NEWPATH="$NEWPATH$colon$entry" && colon=:
+    OLDPATH="${OLDPATH#*:}"
+done
+NEWPATH="$NEWPATH:$OLDPATH"
+export PATH="$NEWPATH"
+unset NEWPATH OLDPATH colon entry search
+
+[[ -n "${DBG}" ]] && echo "${PATH//:/\n}"
+