The region kept the ground inside props of 40 square units or more, and
the steps' extra check of their fourth landing walked agents into box
interiors main never stood them in. Every walled-off floor piece is now
judged by the cone the app paints there (archive aedc41a): a piece where
no spot sees out of it goes, and in the rest only spots that see out or
paint 100 square units stay. The steps are main's again; where they find
nothing, the region places the agent.

Of 4,036 grid drops the region places, 14 paint under 100 square units
(63 before), two of them inside props.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>