feat(schema): add bidirectional relationship identifiers and fabric-device links

- LocationSite: add devices (device__site) and fabrics (fabric__sites) reverse relationships
- InfraDevice.site: add identifier device__site
- InfraDevice: add fabric relationship (fabric__devices)
- InfraFabric.sites: add identifier fabric__sites; add devices reverse relationship (fabric__devices)
- InfraInterfaceVlan.vlan: add identifier vlan__svi
- InfraVLAN: add svi_interfaces reverse relationship (vlan__svi)
- Add 14-fabric-links.yml to assign all 10 devices to the evpn-lab fabric

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

infrahub/schemas/base.yml

@@ -62,6 +62,19 @@ nodes:
         kind: Text
         optional: true
         description: Facility identifier or code
+    relationships:
+      - name: devices
+        peer: InfraDevice
+        identifier: device__site
+        cardinality: many
+        kind: Generic
+        description: Devices at this site
+      - name: fabrics
+        peer: InfraFabric
+        identifier: fabric__sites
+        cardinality: many
+        kind: Generic
+        description: Fabrics deployed at this site
 
   # ================================================================
   # Platform
@@ -145,6 +158,7 @@ nodes:
     relationships:
       - name: site
         peer: LocationSite
+        identifier: device__site
         cardinality: one
         optional: true
       - name: platform
@@ -164,6 +178,12 @@ nodes:
         peer: InfraMlagDomain
         cardinality: one
         optional: true
+      - name: fabric
+        peer: InfraFabric
+        identifier: fabric__devices
+        cardinality: one
+        optional: true
+        description: Fabric this device belongs to
 
   # ================================================================
   # Interface Types (inherit from InfraInterface generic)
@@ -263,6 +283,7 @@ nodes:
     relationships:
       - name: vlan
         peer: InfraVLAN
+        identifier: vlan__svi
         cardinality: one
         optional: true