══ THE STRETCH ══
{n} rows from {t_start} to {t_end}, level {level} container.
{rows}

══ HOW TO RESPOND ══
If a coherent stretch is worth naming AND at least {floor} of these rows
genuinely belong together, emit the propose object. If the material is thin
or the rows don't actually cluster, emit skip — better no container than a
dead-weight one.
