fix(deploy): probe readyz via 127.0.0.1 in update.sh

In the alpine nginx image localhost resolves to ::1 first while nginx
listens on IPv4 only, so the readiness wait never succeeded.

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

deploy/update.sh

@@ -62,7 +62,8 @@ docker image prune -f >/dev/null
 
 echo "→ ждём готовности api"
 for _ in $(seq 1 60); do
-  if docker compose exec -T nginx wget -qO- http://localhost/readyz >/dev/null 2>&1; then
+  # 127.0.0.1, а не localhost: в alpine localhost — сначала ::1, а nginx слушает только IPv4
+  if docker compose exec -T nginx wget -qO- http://127.0.0.1/readyz >/dev/null 2>&1; then
     echo "pipu $VERSION запущен"
     exit 0
   fi