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/Chart.yaml

@@ -1,11 +1,11 @@
 apiVersion: v2
-name: switchboard
-description: Switchboard Core — self-hosted extension platform
+name: armature
+description: Armature — self-hosted extension platform
 type: application
 version: 0.1.0
 appVersion: "0.0.0" # Patched at CI/release time from /VERSION
 home: https://gobha.ai
 sources:
-  - https://git.gobha.me/switchboard/core
+  - https://git.gobha.me/armature/core
 maintainers:
   - name: xcaliber