The rendered /etc/decnet/decnet.ini now carries host-uuid and
swarmctl-port in [agent], which config_ini seeds into DECNET_HOST_UUID
and DECNET_SWARMCTL_PORT. Gives the worker a stable self-identity for
the heartbeat loop — the INI never has to be rewritten because cert
pinning is the real gate (a rotated UUID with a matching CA-signed
cert would still be blocked by SHA-256 fingerprint mismatch against
the stored SwarmHost row).
Also adds DECNET_MASTER_HOST so the agent can find the swarmctl URL
via the INI's existing master-host key.
anti
e411063075