feat(auth): Blessing Skin variant as Drasl alternative

Override stack that swaps Drasl for Blessing Skin Server + MariaDB,
talking to Minecraft via the yggdrasil-api plugin (authlib endpoint
/api/yggdrasil, ONLINE_MODE=TRUE). Caddy auth.* repointed to
blessing-skin:80; Drasl left idle (compose merges depends_on).

Run: docker compose -f docker-compose.yml -f docker-compose.blessingskin.yml up -d

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

caddy/conf.d/00-core-blessingskin.caddy

@@ -0,0 +1,14 @@
+# Core ingress — Blessing Skin variant. Replaces 00-core.caddy when the
+# docker-compose.blessingskin.yml override is in play (mounted at the same
+# target path). auth.* now points at Blessing Skin instead of Drasl.
+#
+# Blessing Skin serves BOTH its web UI (/) and the Yggdrasil API (/api/yggdrasil)
+# on the same vhost, so a single reverse_proxy covers everything.
+http://auth.{$BASE_DOMAIN} {
+	reverse_proxy blessing-skin:80
+}
+
+http://pack.{$BASE_DOMAIN} {
+	root * /srv/pack
+	file_server browse
+}