Set web push urgency

e.g. sendouq match started should be higher priority than "normal". Users report some notifications taking a long time to arrive. Not sure how well browsers support it but might as well try

<img width="683" height="219" alt="Image" src="https://github.com/user-attachments/assets/a907c8f4-169c-4838-b22d-c91421ff53e6" />

https://datatracker.ietf.org/doc/html/rfc8030#section-5.3