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>

chart/templates/deployment-backend.yaml

@@ -3,7 +3,7 @@ kind: Deployment
 metadata:
   name: {{ .Release.Name }}-backend
   labels:
-    {{- include "switchboard.backend.labels" . | nindent 4 }}
+    {{- include "armature.backend.labels" . | nindent 4 }}
 spec:
   replicas: {{ .Values.backend.replicaCount }}
   selector:
@@ -38,7 +38,7 @@ spec:
                 topologyKey: kubernetes.io/hostname
       containers:
         - name: backend
-          image: {{ include "switchboard.backend.image" . }}
+          image: {{ include "armature.backend.image" . }}
           imagePullPolicy: {{ .Values.backend.image.pullPolicy }}
           ports:
             - name: http
@@ -48,10 +48,10 @@ spec:
             - configMapRef:
                 name: {{ .Release.Name }}-config
             - secretRef:
-                name: {{ include "switchboard.secretName" . }}
+                name: {{ include "armature.secretName" . }}
           env:
             - name: DATABASE_URL
-              value: {{ include "switchboard.databaseURL" . | quote }}
+              value: {{ include "armature.databaseURL" . | quote }}
           resources:
             {{- toYaml .Values.backend.resources | nindent 12 }}
           {{- if .Values.persistence.enabled }}