/usr/lib/Wt/examples/planner/resources is in witty-examples 3.3.0-1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/Wt/examples/planner/../../../../share/Wt/resources
/usr/lib/Wt/examples/planner/../../../../share/Wt/resources