Core Rule Set: Nextcloud's calendar and contacts sync pass (closes #280)

rproxy passes MKCALENDAR on. nextcloud.conf allows it on
/remote.php/dav/calendars/ and PROPFIND on /.well-known/caldav and
carddav. The XML of an MKCOL there skips 930120, 932120, 932250 and
932260. That of an MKCALENDAR, and of an MKCOL on the address books'
paths, also skips 932125 and 932230, for the description. A PUT of
text/calendar or text/vcard there skips 920530: the Calendar and
Contacts apps name the charset twice when they change an event or a
contact.

Recorded from Nextcloud 35.0.2 with Calendar 6.6.5, Contacts 8.9.5 and
requests imitating DAVx5.

Model: opus-5-5

internal/rproxy/rproxy.go

@@ -53,7 +53,7 @@ const ownEndpointPrefix = "/_sww/"
 // them. It answers any other method 405 itself.
 // The WebDAV ones are for Nextcloud.
 const allowedMethods = "GET, HEAD, POST, OPTIONS, PUT, DELETE, PATCH, QUERY, " +
-	"PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, REPORT, SEARCH, LOCK, UNLOCK"
+	"PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, REPORT, SEARCH, LOCK, UNLOCK, MKCALENDAR"
 
 // Params are what New needs.
 type Params struct {