The curriculum composer committed on question SHAPE — any `Does …?` text —
and then, being fail-closed, always returned a surface. With the flag on,
"Does the build pass?" would have been taken away from the rest of dispatch
and answered "I haven't been taught the or pass"; "Does anyone know the
time?" likewise. Found by checking the flag's readiness before recommending
ratification; never live, since the flag is default-off.
The asymmetry is the lesson: the deduction composer may commit on shape
because a sentence-initial "therefore" IS a signal of intent — text shaped
that way is an argument. `Does …?` is one of the most common ways to open
any English question and signals nothing. A fail-closed composer is only as
safe as its commit gate is narrow.
The gate is now `is_curriculum_question`: claim the turn only when the
question parses to three tokens AND its terms are vocabulary a served
subject actually teaches. Everything past the gate stays fail-closed —
including `ambiguous_reading` (both terms taught, two subjects claim them)
and `out_of_curriculum` (terms taught, relation unknown), which are real
curriculum questions with honest answers. The DECIDER is unchanged, so the
lane still records untaught-vocabulary probes as declined: the curriculum
path declines them AND does not speak for them.
[Verification]: tests/test_curriculum_serve.py 28 passed (+8: five ordinary
`Does …?` questions pass through untouched, three routable ones still
answered); core test --suite deductive 268 passed; curriculum lane 32/32
wrong=0 with its pinned report SHA unchanged.