§12a. Runtime-settable options

planarian @ a924e09 · Spec v4.6 · snapshot main · all versions

A core-owned allowlist (Sensitivity::Core; not extensible by manifest or model) of options whose effect can be applied immediately: font scale, volume, brightness, keyboard layout, Wi-Fi network selection. SetRuntimeOption applies the effect as a Runtime transition (subject to the global floors: Wi-Fi selection has ConnectivityLoss, none while NetworkManager has already failed, §11), then enqueues an ApplyChange write-back whose expectation is “no unit changes.” If the write-back’s build or probes fail, the runtime change stays in effect, the write-back is Reverted (override source untouched), the console shows “this setting will not survive reboot,” and the incident manager does not retry it; the user may re-issue it. The write-back is never attempted while a generation transaction is active: it is queued behind the active transaction and submitted when that transaction is terminal, with the same caller. A write-back refused as busy is not a failure and produces no notice.