Documented as "kept for backwards import compatibility", it had zero
production callers - only its own two tests. Removed the function, those
two tests, and the pathlib.Path import that only its signature used.
_SEC_PER_DAY stays: two live callers remain at _usage_report_run.py:135
and :181, so only the function was dead, not the constant.
Verified: usage_report.py --help exits 0 (the unit tests stub subprocesses,
so only a real run proves the import graph), 202 tests pass, and
_usage_report_run.py holds 100% line+branch coverage after removing both
the code and the tests that covered it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011w2Pj4Ek3ZNMQVYcFHgXDY
