add book_count feature, migrate backoffice to server actions, fix healthcheck

infra/docker-compose.yml

@@ -96,15 +96,15 @@ services:
     env_file:
       - ../.env
     environment:
-      - PORT=${BACKOFFICE_PORT:-8082}
-      - HOSTNAME=0.0.0.0
+      - PORT=8082
+      - HOST=0.0.0.0
     ports:
       - "${BACKOFFICE_PORT:-8082}:8082"
     depends_on:
       api:
         condition: service_healthy
     healthcheck:
-      test: ["CMD", "wget", "-q", "-O", "-", "http://127.0.0.1:8082/health"]
+      test: ["CMD", "wget", "-q", "-O", "-", "http://host.docker.internal:8082/health"]
       interval: 10s
       timeout: 5s
       retries: 5