Add support for multi-system BMCs

[damyan]

When meeting a BMC with multiple systems, the metal-operator seems to take a random (first?) one to populate the BMC status.

Proposal: create system heuristics, based on which the server object shall be created out of the right system, ignore all the rest systems

Current behavior:

curl -sku "$u:$p" https://$BMC_URL/redfish/v1/Systems/ | jq .Members
[
  {
    "@odata.id": "/redfish/v1/Systems/1"
  },
  {
    "@odata.id": "/redfish/v1/Systems/HGX_Baseboard_0"
  }
]

kubectl get bmc ai-wdf4a-1 -o yaml
apiVersion: metal.ironcore.dev/v1alpha1
kind: BMC
metadata:
  name: foo
  uid: 89fb09fc-dd12-4a9f-86da-834ae9ae3858
  […]
spec:
  bmcSecretRef:
    name: ai-wdf4a-1
  consoleProtocol:
    name: SSH
    port: 22
  endpointRef:
    name: foo
  protocol:
    name: Redfish
    port: 443
status:
  conditions:
  - lastTransitionTime: "2026-04-22T14:21:26Z"
    message: BMC is connected
    reason: BMCConnected
    status: "True"
    type: Ready
  ip: […]
  lastResetTime: "1970-01-01T00:00:00Z"
  macAddress: [BMC_MAC_ADDRESS]
  powerState: Unknown
  state: StandbyOffline

kubectl get servers ai-wdf4a-1-system-0 -o yaml
apiVersion: metal.ironcore.dev/v1alpha1
kind: Server
metadata:
  creationTimestamp: "2026-04-22T14:21:31Z"
  generation: 5
  name: foo-system-0
  ownerReferences:
  - apiVersion: metal.ironcore.dev/v1alpha1
    blockOwnerDeletion: true
    controller: true
    kind: BMC
    name: ai-wdf4a-1
    uid: 89fb09fc-dd12-4a9f-86da-834ae9ae3858
  resourceVersion: "88976872"
  uid: 5ea93962-861d-41b2-a180-36369fc6ad42
spec:
  bmcRef:
    name: foo
  systemURI: /redfish/v1/Systems/HGX_Baseboard_0
  systemUUID: ""
status:
  state: Initial

kubectl get servers ai-wdf4a-1-system-1 -o yaml
apiVersion: metal.ironcore.dev/v1alpha1
kind: Server
metadata:
  creationTimestamp: "2026-04-22T14:21:31Z"
  generation: 5
  name: foo-system-1
  ownerReferences:
  - apiVersion: metal.ironcore.dev/v1alpha1
    blockOwnerDeletion: true
    controller: true
    kind: BMC
    name: foo
    uid: 89fb09fc-dd12-4a9f-86da-834ae9ae3858
  resourceVersion: "88976873"
  uid: 2d96bb22-d292-4702-b311-f65543f6ad81
spec:
  bmcRef:
    name: foo
  systemURI: /redfish/v1/Systems/1
  systemUUID: 00000000-0000-0000-0000-[BMC_MAC_ADDRESS]
status:
  state: Initial

[afritzler]

A possible solution for this issue would be:

1. Filter out managers which are not related to "bootable" systems
2. Filter out system which can not be booted

The filtering can be done using heuristics by expecting certain fields being present when listing managers and systems.