ff59fcd710
DEFERRED_INDEX_SQL unconditionally DROPs and re-CREATEs the four display triggers on every open so a changed trigger body rolls out; DROP TRIGGER IF EXISTS on an existing trigger takes the write lock, so a settled database still blocked behind a sibling's transaction after the three statement gates. Compare each trigger's stored sql against the desired CREATE text and run the pair only when they differ. CREATE ... IF NOT EXISTS forms are lock-free on an existing object and run as written. The no-writes test now also traces DROP TRIGGER / ALTER.