feat(caddy): add Caddyfile (apex + auth + packwiz vhosts)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

caddy/Caddyfile

@@ -0,0 +1,17 @@
+{
+	auto_https off
+}
+
+http://{$BASE_DOMAIN} {
+	root * /srv/www
+	file_server
+}
+
+http://auth.{$BASE_DOMAIN} {
+	reverse_proxy drasl:25585
+}
+
+http://packwiz.{$BASE_DOMAIN} {
+	root * /srv/pack
+	file_server browse
+}