Replace the workspace's web analytics settings

Gated by the web_analytics write permission (like blog settings, members manage the feature without workspace write access). The attribution filters version is recomputed server-side. Passing null settings clears the configuration.

Writing an identified visitor's goals and navigation to their contact timeline is not configured here and has no setting: calling identify() with an HMAC is the opt-in, because minting that credential requires the workspace secret.