Building a CalDav server

There are good ideas, bad ideas and the ideas I get when sitting on a couch holding the paw of my dog for two weeks (while she is recovering from surgery). One thing I am really not a fan of is the current landscape of CalDav servers. So what better to do than read some RFCs while a coding agent bootstraps a “kind of not working but close enough” skeleton that I can make actually work in between treats, all the pets required for recovery and "who is the best girl?! YOU ARE THE BEST GIRL!". “But… Why?”, you might rightfully ask. First, because I can. (Same answer as always.) Second, because I want to keep my calendar and appointments on infrastructure I control. And third, because the current landscape of self hosting a CalDav server does not look too hot, if you ask me. I cannot make it worse than it already is. One feature I am missing with most existing solutions is sending invites via email to attendees of a meeting and seeing their responses. Something you get used to pretty…