answerBatch kept every settled reply in its pending array until the
batch ended, so a batch alternating data/add and data/get held each
loaded state alive; each reply now leaves the queue as it is encoded.
The exact-number policy judged a number by its recorded spelling, so a
state loaded with 1e20 came back from data/get as
100000000000000000000, which data/add refused, breaking the promise
that data/get output loads back unchanged. A number is exact only when
both its recorded spelling and the one serialization writes are safe,
so integers from 2^53 below 1e21 are refused in any spelling; replay
keeps such bodies as recorded text. A domain test checks that every
accepted number is accepted again once written back.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
