DAV was internal-only (the node's :443 is Traefik's). New mail-dav
Ingress routes /.well-known/caldav, /.well-known/carddav and /dav on
mail.dezky.eu through to Stalwart — with the HTTPS-redirect middleware
(safe for DAV's GET/PROPFIND; kept OFF the autodiscover Ingress whose
POSTs don't survive redirects). The _caldavs/_carddavs SRV records are
now legitimate, so the Domains page surfaces them, and the Apple
.mobileconfig gains CalDAV + CardDAV payloads: one install sets up Mail,
Calendar and Contacts on Mac/iPhone. Stalwart's STALWART_PUBLIC_URL is
set to https://mail.dezky.eu on the host (discovery documents).
Apple Mail ignores RFC 6186 SRV autodiscovery and 'Microsoft Exchange'
needs EWS/EAS that Stalwart doesn't speak — so custom-domain users were
stuck typing IMAP/SMTP servers manually. New session-gated portal route
generates an Apple configuration profile (IMAP 993 + SMTP 465 on the
runtime mail host, username = address, NO password embedded — profiles
are plaintext, Apple prompts at install). 'Add to Apple Mail' buttons on
the three credential screens (invite result, mailbox created, password
reset). CalDAV/CardDAV payloads join when DAV is reachable from outside
(the node's :443 belongs to Traefik for now).