Notification sound / favicon change + JS event listener for persistent notifications

Is your feature request related to a problem? Please describe.
Currently, when users receive notifications (especially persistent ones), there is no visual or audio indication unless they are actively looking at the notification area.

This creates a usability issue — users may miss important events because:

• No sound is played
• Favicon does not change
• No browser-level signal appears
• No JS hook exists to react programmatically

This is especially frustrating in back-office workflows where real-time awareness matters.

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Describe the solution you'd like
It would be great to have built-in support for signaling incoming notifications, for example:

• Optional notification sound
• Favicon badge / change
• Browser tab title change

Additionally, it would be very useful to expose a JavaScript event listener that fires when persistent notifications change.

Example API idea:

document.addEventListener('orchid:notification', function (event) {
    console.log('Notification updated', event.detail);
});

This would allow developers to implement custom behaviors such as:

• Playing custom sounds
• Updating favicon badges
• Triggering toast popups
• Integrating with external UI systems

The event could fire when:

• A new persistent notification appears
• Notification state changes
• Notification is removed/read

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Describe alternatives you've considered

Workarounds currently include:

• Polling notification endpoints manually
• DOM mutation observers
• Custom broadcasting implementations
• Replacing the notification system entirely

However, these approaches are brittle, inefficient, and tightly coupled to internal markup.

A native event would be cleaner and more extensible.

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Additional context

This feature would significantly improve UX for admin panels and monitoring dashboards built on the platform.

It also enables richer integrations without modifying core code.