ata-validator

Two fixes and one cost removed.

The tier-0 validator that answers a fresh instance's first calls accepted NaN and Infinity for number, so a validator could change its mind about the same value between its first call and its third, and permanently under a blocked-codegen CSP. Non-finite numbers are now rejected on every path, cold and warm, and a new engine-agreement test holds the line.

A rejection on the buffer path no longer pays a second full walk of the document when the bytecode plan has already decided: reject cost now matches accept cost at every payload size measured, guarded by a ratio test in CI.

The aot entry's type declarations accept the same schema arrays the static methods accept.