Add Ansible playbook to deliver validator-agent to the validators

Run from the jump host: on each validator it updates the git clone in
/opt/cloud-ip-validator, builds the image there, stops and removes the
current container and starts a new one from the new image. Run
parameters live in an env file (deploy/ansible/env/validator-agent.env,
git-ignored, template committed).

The image is built before the running container is touched, so a failed
build leaves the old container running. Hosts are updated in waves
(1, 4, rest) and any failure stops the run. validator_id comes from the
inventory and is checked against the running container before it is
replaced. Only ansible.builtin modules are used, so the validators need
no extra packages.

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

docs/SETUP.md

@@ -739,6 +739,10 @@ docker compose up -d --build
 сборке) и `docker rm -f <имя> && docker run ... ` (или `docker restart`,
 если менялись только переменные окружения, а не сам бинарник/образ).
 
+Для массового обновления валидаторов (git-клон, сборка образа на хосте,
+замена контейнера, проверка регистрации) есть Ansible-сценарий:
+[`deploy/ansible/`](../deploy/ansible/README.md).
+
 ### Диагностика Docker-развёртывания
 
 - **Контейнер сразу падает, в логах `exec format error`** — образ собран