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>

roles/docker/templates/Caddyfile.j2

@@ -126,19 +126,7 @@ repaircafe.nerder.land {
     redir /volunteer-signup https://listmonk.nerder.land/subscription/form 301
 }
 
-{% if vault_dir2opds is defined %}
-opds.thesatelliteoflove.com {
-    basicauth {
-        {{ dir2opds_basic_auth_hash_result.stdout }}
-    }
-    reverse_proxy dir2opds:8080
-}
-{% endif %}
-
 gokapi.thesatelliteoflove.com {
     reverse_proxy gokapi:53842
 }
 
-sync.thesatelliteoflove.com {
-    reverse_proxy kosync:17200
-}