Provide a configurable, real-time notification system that alerts users about order lifecycle events and price proximity to user-defined thresholds. The system should generate alerts for events including order fully filled, partially filled, canceled (by user or system), rejected, and expired. It should also notify when market price approaches configured stop-loss or target levels (by absolute distance or percentage). Notifications must be deliverable via in-app popups, browser/OS push notifications, and optional email, with per-user controls to enable/disable channels and event types. Users should be able to set proximity criteria (percentage or fixed price), customize basic message templates, and specify throttling/aggregation settings to avoid notification spam. The implementation should guarantee near real-time delivery, record notification history for audit/debugging, and expose settings in the UI for managing preferences and thresholds. This enables users to monitor execution status and manage risk more effectively by receiving timely, actionable alerts.
