Retire kosync and dir2opds now that Kavita handles both

Kavita's KOReader sync API and OPDS feed replace them, and both readers
(Kindle KOReader, Xteink X4) now point at books.thesatelliteoflove.com.
Drops their stacks, the sync. and opds. routes and DNS records, and the
htpasswd tasks that only existed for dir2opds basic auth.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

group_vars/all/domains.yml

@@ -25,8 +25,6 @@ subdomains:
   gotify: "gotify.{{ primary_domain }}"  # Gotify notifications
   gotify_assistant: "gotify-assistant.{{ primary_domain }}"  # iGotify iOS assistant
   listmonk: "listmonk.{{ secondary_domain }}"  # Listmonk mailing list
-  dir2opds: "opds.{{ primary_domain }}"  # dir2opds OPDS catalog
-  kosync: "sync.{{ primary_domain }}"  # KOReader sync server
   gokapi: "gokapi.{{ primary_domain }}"  # Gokapi file sharing
   pocketid: "id.{{ primary_domain }}"  # Pocket ID passkey OIDC