Adds four regression tests guarding the bugfix in the previous commit:
- TestGetDueJobs::test_broken_cron_without_next_run_is_recovered exercises
cron schedules whose next_run_at was lost; expects compute_next_run to
repopulate it within get_due_jobs() rather than silently skipping the job.
- TestGetDueJobs::test_broken_interval_without_next_run_is_recovered does
the same for interval schedules.
- TestResolveOrigin::test_string_origin_is_tolerated and
test_non_dict_origin_is_tolerated confirm _resolve_origin() returns None
for legacy/hand-edited origins (string, list, int) instead of raising.
Co-Authored-By: Claude <noreply@anthropic.com>
645b99aadd