Herbs that keep producing on a windowsill

Sprint 16 established that the honest answer for most windowsill herbs is 'until October', and Sprint 22 made it a field. Filtering on whether the herb will actually grow indoors returns thirty-two of thirty-three, because almost anything survives a windowsill; filtering on whether it keeps PRODUCING returns twenty-one, and the twelve it excludes are the ones people buy most. A supermarket basil is fifteen seedlings in one plug and dies on schedule, coriander bolts from a single check, and neither is a failure of care. This is that distinction as a list.