AprilTag missed detection nudge for AR users

[mwfarb]

Issue: When new users attempt to use ARENA, especially using AR features, depending on the situation they may not be aware they should be pointing the the mobile device camera. Example: User turns on AR for a scene, but is facing away from AprilTag at the time.

Solution: Potentially, in general, it would be good to detect the user is in immersive AR, and if an AprilTag is registered somewhere in the scene, we have an opportunity to guide them to their first "detection" if it hasn't already happened.

Options:

• Send a MQTT event for "missed first detection", after some seconds, allowing a client program a chance to decide how to notify the user.
• Create a UI response on the web to show a message or icon alert with some guidance to point the camera to the AprilTag.
• Others?