Unit tests for Karel the Robot's CSV export: inspect CSV contents

Unit tests don't cover the CSV export from Karel. Should test beepers (0, 1 or more), walls (including near edges), and karel's position and orientation.

Locate the Karel the Robot CSV export implementation and the existing unit-test setup, then inspect how exported worlds represent beepers, walls, and Karel's position and orientation. Add tests covering zero, one, and multiple beepers, walls near edges, and each position/orientation case; done means the tests verify the CSV contents.

Written by the indexing model from the issue text.