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>

docs/ARCHITECTURE.md

@@ -1,6 +1,6 @@
-# Switchboard Core — Architecture
+# Armature — Architecture
 
-Switchboard Core is a self-hosted extension platform. It provides identity,
+Armature is a self-hosted extension platform. It provides identity,
 teams, permissions, storage, workflows, notifications, and a package system.
 Everything else — chat, AI providers, personas, knowledge bases, notes,
 tools — ships as installable extensions.
@@ -284,7 +284,7 @@ Single Docker image: Go binary + migrations + frontend assets + vendor
 libs. Kubernetes deployment with 3-node PG cluster. CI via Gitea Actions
 with DaemonSet DinD runners testing both PG and SQLite pipelines.
 
-Registry: `registry.gobha.me:5000/xcaliber/switchboard-core`
+Registry: `registry.gobha.me:5000/xcaliber/armature`
 Namespace: `gobha-ai-chat`
 
 ### Cluster Topology