Whether a column has a reader anywhere in the tree is a whole-program property,
and grep is the only cheap approximation. Grep is unsound both ways here:
generic names match unrelated identifiers and read as consumed, while
consumption through a select-less read plus whole-row serialization reads as
unconsumed. A gate built on that would drift towards green and stop meaning
anything, which is the failure this whole line of work exists to prevent. So it
stays a review tool with a human reading the output, run from the deep-audit
step and never in CI. The script says so itself and prints the false-positive
sources under every run.
It also carries the convention that makes the tool useful: a change that adds a
column, payload field, or preference contains its consumer, or the schema
comment carries `@internal` for something deliberately never surfaced or
`@pending-consumer(#issue)` for one still coming. The second marker is
re-listed on every run, so a follow-up that never happened surfaces at the next
release audit instead of never. Recorded in the contributor notes alongside the
two questions that are exact enough to be gates.
