feat(fc-devicemgmt): add Kubernetes deployment manifests (#1)

Sprint 8 IMPL lane Cx-5: fc-devicemgmt K8s manifests (rebased onto main 2026-05-18; 13 files, +944).

Namespace + Web Deployment (replicas:2, MySQL backend) + Operator Deployment (replicas:1, KubeOps leader-elect) + Service + Certificate (step-ca-acme ClusterIssuer) + Traefik IngressRoute (devices.iamworkin.lan internal) + ServiceAccount + ClusterRole + ClusterRoleBinding + NetworkPolicy (CNI DNAT-aware backend ports) + OnePasswordItem (5-field consolidated) + ArgoCD Application bootstrap shape + lint coverage.

Follow-ups (not merge blockers):
- localhost/fc-devicemgmt-{web,operator}:v20260512-cx5 must be imported to all 3 RKE2 nodes; pods will ErrImageNeverPull until imported.
- 1Password vault item 'FlowerCore DeviceManagement Runtime' must be created with 5 fields before pods can start.
- DNS devices.iamworkin.lan -> 10.0.56.200 already present.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

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