Update User Personalization

Merge a patch into a user's account-level personalization document.

Body is a PARTIAL document — send only the top-level key you own: {"notifications": {"email_updates": true, "push_enabled": false, "agreed_at": "..."}} {"parental_consent": {"agreed": true, "agreed_at": "..."}} {"account_details": {"goals": [...], "referral_source": "..."}}

This is a MERGE, not a replace: the write happens inside a single personalization || p_patch statement, so independent writers touching different keys cannot lose each other's updates. Onboarding writes account_details and parental_consent; the notifications screen and Settings write notifications — all potentially close together.

|| is shallow, so a patched top-level key is replaced whole. Each writer must send its own key complete rather than a nested fragment.

Writes only the personalization column, never persona. Does NOT invalidate the For You cache — nothing here feeds recommendations.