The helper under test writes to os.environ directly, bypassing
monkeypatch tracking. Without an explicit snapshot/restore fixture,
the mutation leaks into subsequent tests and breaks TestSharedBoardPaths
(kanban path resolution reads HERMES_KANBAN_BOARD and routes through
boards/<leaked-slug>/ instead of the test's own HERMES_HOME).
Add an autouse fixture that snapshots the env var before the test and
restores (or pops) it after, regardless of what the helper did.
Teknium
f8a6db68ca