test(cron): cover CLI helper functions

[xuezhaolan]

Summary

• add direct unit coverage for cron_list, cron_status, cron_tick, and cron_create
• assert gateway-running and gateway-missing output paths without shelling out
• keep existing command lifecycle coverage intact while updating edit/create arg fixtures for current CLI fields

Test Plan

• python -m pytest tests/hermes_cli/test_cron.py -q -o addopts=
• git diff --check

Closes #35727

[teknium1]

This coverage has landed on main via #59510 (commit 3ba5ba8) — your original commit was cherry-picked with co-author credit preserved. Thanks @xuezhaolan for the contribution!