feat(fc-devicemgmt): add Kubernetes deployment manifests

apps/fc-devicemgmt/namespace.yaml

@@ -0,0 +1,13 @@
+# FlowerCore.DeviceManagement namespace.
+#
+# ArgoCD discovers this directory as Application `infra-fc-devicemgmt`.
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: fc-devicemgmt
+  labels:
+    app.kubernetes.io/name: fc-devicemgmt
+    app.kubernetes.io/part-of: flowercore
+    app.kubernetes.io/managed-by: argocd
+    flowercore.io/tenant-id: system
+    flowercore.io/created-by: bluejay-infra