`until "A"; pause; until "B"; pause` renamed .until over .until.pause and A was
gone — silently, with no backup. Pausing again is exactly what a user does after
setting a condition mid-pause, so that was the moment it destroyed data.

A second pause now folds the live conditions into what is already set aside,
continuing past its lastId so no id is ever reused, and skipping a text that is
already there (so re-setting the same condition can't double it — resume dedupes
the same way). The marker's line format now has ONE writer, so the live store and
the set-aside one cannot drift.

Closes #403