feat(vm_provision_mixin): expose fixed_vlan_tag for SDN vnets

vnet's SDN tag (VLAN ID) is now surfaced in get_network_targets() output
instead of being silently discarded. Bridges never set this field.

napalm_proxmox/vm_provision_mixin.py

@@ -415,6 +415,15 @@ class ProxmoxVMProvisionMixin:
             if not name:
                 continue
             # A vnet's VLAN is already fixed by its zone/tag — no separate vlan_tag applies.
-            targets.append({"name": name, "kind": "vnet", "vlan_aware": False})
+            tag = vnet.get("tag")
+            fixed_vlan_tag = int(tag) if tag is not None else None
+            targets.append(
+                {
+                    "name": name,
+                    "kind": "vnet",
+                    "vlan_aware": False,
+                    "fixed_vlan_tag": fixed_vlan_tag,
+                }
+            )
 
         return targets

tests/test_vm_provision_mixin.py

@@ -472,3 +472,42 @@ def test_get_network_targets_sdn_vnet_never_vlan_aware():
     assert len(targets) == 2
     assert all(t["kind"] == "vnet" for t in targets)
     assert all(t["vlan_aware"] is False for t in targets)
+
+
+def test_get_network_targets_vnet_exposes_fixed_vlan_tag():
+    """A vnet's fixed_vlan_tag surfaces its SDN tag for display purposes."""
+    mixin = ProxmoxVMProvisionMixin()
+    mixin._get_node_network = MagicMock(return_value=[])
+    mixin._get_sdn_vnets = MagicMock(
+        return_value=[{"vnet": "vnet0", "zone": "zone-vlan", "tag": 10}]
+    )
+
+    targets = mixin.get_network_targets()
+
+    assert targets[0]["fixed_vlan_tag"] == 10
+
+
+def test_get_network_targets_vnet_without_tag_has_none_fixed_vlan_tag():
+    """A vnet with no tag (e.g. VXLAN/EVPN zone) reports fixed_vlan_tag=None."""
+    mixin = ProxmoxVMProvisionMixin()
+    mixin._get_node_network = MagicMock(return_value=[])
+    mixin._get_sdn_vnets = MagicMock(
+        return_value=[{"vnet": "vnet2", "zone": "zone-vxlan"}]
+    )
+
+    targets = mixin.get_network_targets()
+
+    assert targets[0]["fixed_vlan_tag"] is None
+
+
+def test_get_network_targets_bridge_has_no_fixed_vlan_tag():
+    """Bridges never carry a single fixed VLAN tag — only vnets do."""
+    mixin = ProxmoxVMProvisionMixin()
+    mixin._get_node_network = MagicMock(
+        return_value=[{"iface": "vmbr0", "type": "bridge", "bridge_vlan_aware": 1}]
+    )
+    mixin._get_sdn_vnets = MagicMock(return_value=[])
+
+    targets = mixin.get_network_targets()
+
+    assert "fixed_vlan_tag" not in targets[0] or targets[0]["fixed_vlan_tag"] is None