Toggles subscription to notifications for a given client.
Subscribes or unsubscribes all registered notification handlers based on the 'active' flag.
Stores bound handlers on target as __handler${notificationName} so subscribe/unsubscribe use the same reference (no WeakMap; Roku-compatible).
If a bound handler already exists for a notification name when subscribing, it is unsubscribed first.
Toggles subscription to notifications for a given client. Subscribes or unsubscribes all registered notification handlers based on the 'active' flag. Stores bound handlers on
targetas__handler${notificationName}so subscribe/unsubscribe use the same reference (no WeakMap; Roku-compatible). If a bound handler already exists for a notification name when subscribing, it is unsubscribed first.