rebrand: Switchboard Core → Armature

- Rename Go module switchboard-core → armature (155+ files)
- Rename Docker image → gobha/armature
- Rename K8s resources, secrets, deployments
- Rename Prometheus metrics switchboard_* → armature_*
- Rename env vars SWITCHBOARD_ADMIN_* → ARMATURE_ADMIN_*
- Rename DB names switchboard_core* → armature*
- Update all frontend branding, notification templates, docs
- Update CI scripts, e2e tests, Keycloak realm, nginx conf
- Rename scripts/switchboard-ca.sh → scripts/armature-ca.sh
- Rename k8s/switchboard.yaml → k8s/armature.yaml
- Rename chart alerting/dashboard files
- Fix: DockerHub push uses env: binding for secret injection
- Helm chart updated (name, labels, template functions, dashboard, alerting)
- Replace favicon/icon assets with Armature brand

No functional changes. Pure mechanical rename + CI fix.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

k8s/rbac-traefik.yaml

@@ -16,7 +16,7 @@ metadata:
   name: traefik-middleware-manager
   namespace: ${NAMESPACE}
   labels:
-    app: switchboard
+    app: armature
 rules:
   - apiGroups: ["traefik.io"]
     resources: ["middlewares"]
@@ -28,7 +28,7 @@ metadata:
   name: gitea-runner-traefik-middleware
   namespace: ${NAMESPACE}
   labels:
-    app: switchboard
+    app: armature
 subjects:
   - kind: ServiceAccount
     name: gitea-runner-sa