drop duration gate on [OPERATIONAL HISTORY]
Conflated two things in the previous patch: recording always happens
(record_paused/resumed write to disk regardless of duration), but the
prompt block was suppressing short pauses on the assumption that they
were too trivial to surface. That's a value judgment phi gets to make,
not us. Remove the 10-min floor; the 24h "since resume" window is
sufficient to keep stale data out of the prompt.