fix(notification): defer sound until first render

[aefly]

Summary

When two or more plugins have an update available, the notification sound played several times in a row immediately, before the second popup appeared.

SPF_NOTIF_MODE_TOP displays only one notification at a time; the others wait in a queue. However, NotificationWindow::ShowEx played the sound as soon as the notification was enqueued. With N queued TOP notifications, the sound fired N times at once, and the later popups then appeared silently.

This affects any burst of TOP notifications (plugin update notices, framework update notice, plugin API calls).

Fix

• Add a pendingSound flag to NotificationData.
• ShowEx no longer plays the sound; it only sets pendingSound (same condition as before: sound enabled and mode is not STICKY).
• RenderSingleNotification plays the sound on the notification's first render and clears the flag. Since queued TOP notifications are not rendered until they become active, each one now plays its sound when it actually appears.

STACK notifications are unaffected: they are rendered on the next frame, so their sound plays as before.

[TrackAndTruckDevs]

Thanks, merged.
How critical is this fix for your MotionCab? I planned to release in a week or two, when I've written more functionality, but if it's critical I can put out a mini-release...

[aefly]

None, everything is good from SPF, just taking my time to release the new version, in some days.

Thanks for asking!