fix: secure lab deployment defaults

[vtino17]

Summary

• replace the Grafana changeme password with a Docker secret
• bind the Wazuh indexer, Prometheus, and Grafana to loopback
• detect Docker Compose v2 correctly
• validate MikroTik targets, require an explicit password, upload configs before import, and use host-key trust-on-first-use
• add deployment safety regression tests

Validation

• bash -n scripts/deploy.sh tests/test_deploy_safety.sh
• bash tests/test_deploy_safety.sh
• git diff --check

Docker Compose is not installed in the local environment, so the composed stack remains to be validated in a Docker-enabled reviewer environment.