Synthetic cross rate is floor-quantized onto the 8-decimal grid before the anchored band is built

Confidence delta is floored in the oracle's 8-decimal domain, so the uncertainty component truncates to exactly zero for low-priced feeds

Floored mid with full-precision spread sinks the band

`ChainlinkOracle` passes a token fee quote to `verify` while having no code path that can ever grant an allowance