Get account notification preferences

GET /v1/notifications/preferences

Read Core account preferences shared across desktop, mobile and email. Returns { sections: { chat, strategy, trade }, mandatorySections: ["billing", "important"], strategies: [{ id, name, onTradeFill }] }. Billing and Important are always enabled. Strategy controls the entire strategy section, including fills, seats and fee changes. strategies lists active subscriptions only; id is the published strategy ID, resolving the current user's active subscription. New subscriptions default to enabled. Own runs without a subscription row have no individual override. These preferences do not change this device's system-notification permission or ordinary local Chat/Coding notifications.