[Bug]: alpha hanging on every open, can't interact with app

### What Monal Release channel are you using? Alpha ### iOS system version (if applicable) _No response_ ### macOS system version (if applicable) 25.5 ### Monal version 2026-05-20T15:05:13+02:00 ### Used XMPP server (domain) disroot.org ### Which XMPP-Server software are you using? Prosody ### XMPP Server Software Version _No response_ ### How many accounts are you using in Monal? 2 ### What happened? Opening the alpha results in a stuck state with the spinner on top of the chat list spinning indefinitely. macOS shows alpha as not responding. Force quitting results in the following report (1 year): https://bin.disroot.org/?75d83519b6dfe622#7scFnTKdEiztNooFwaKu2Wo4jRtsCZeLrDscjVEm27Qb ### Anything else? _No response_ ### FAQ - [x] I have [checked the FAQ](https://github.com/monal-im/Monal/wiki/FAQ---Frequently-Asked-Questions) for my issue ### Considerations for XMPP users - [x] I have checked if my issue can be solved with [Considerations for XMPP users](https://github.com/monal-im/Monal/wiki/Considerations-for-XMPP-users) and [Considerations for XMPP server admins](https://github.com/monal-im/Monal/wiki/Considerations-for-XMPP-server-admins) ### XEP-Check - [x] I have checked that at least XEP-198, XEP-0280, XEP-0352, XEP-0357, XEP-0313 and XEP-0163 are activated on my server and shown as 'green' under Settings --> Account--> (i) in advanced settings ### Notifications-Menu - [x] I have checked that all checkmarks are present under Settings --> Notifications