The deferral helpers from the previous commit were appended to the cron/scheduler.py facade and
carried ~70 lines of fallbacks (getattr/callable checks, result() waits, a teardown_registered
flag) for hypothetical Future doubles; the only producer is _cron_pool.submit, always a real
concurrent.futures.Future whose done()/add_done_callback() cannot raise. Also drops the
_finalize_cron_session_db passthrough. Behaviour unchanged; the test now asserts the
finalize+teardown contract on the real Future instead of a patched wrapper.
kshitijk4poor
40488a4e54