HA runtime template contexts (shell_command {{ }} rendering) cannot read
secrets.yaml; kuma_push_url rendered undefined every fire and the Kuma
push dead-man never sent a beat. Move the full curl command into the
secret (kuma_heartbeat_cmd) and reference it with !secret, which is
substituted at config parse where secrets work.
On-box fix applied + verified under GLPI CR 21; this commit makes the
git copy match the deployed state.
Ticket: https://projects.knownelement.com/issues/811
CR: https://cmdb.knownelement.com/front/change.form.php?id=21
ic-builder