Overwrite deps info browserHash only on commit

Editor assessment

`fix: overwrite deps info browserHash only on commit` states the field, the restricted timing, and the operation precisely; an optimizer scope would have localized it but the internal term does that work. Fix fits a premature-write bug. No body explains what early writes corrupted, such as cache validation — the instructive detail — but the subject fully determines the change. The trailing PR reference is clean. Imperative verb, no trailing period, compact. Minor rationale gap in a clear, correct, publishable message.