Creates Docker Swarm secrets from selected HashiCorp Vault KV v2 keys. The secret is created with a name pattern of {key}-{hash} of the value bytes.

Statuses:

• created — the secret has been created.
• skipped — the secret already exists, skipping the step.

Secret values are never written to the build log.

The step sets build environment variables (uppercase, - → _):

• rabbitmq-signing-key → RABBITMQ_SIGNING_KEY
• rabbitmq_default_user → RABBITMQ_DEFAULT_USER

Use these variables later in the Portainer Stack Deployment step.