projectsFromColumns

Whether every projected field is bound to a shredded column that can reconstruct it exactly.

A fact about the plan, decided before a row is produced, which is why it belongs here rather than only in QueryStats.rowsProjectedFromColumns. true does not promise every row avoids its document — a residual ordinal still needs one — so the two answer different questions and a test that means "push-down fired" wants the counter.