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>

Dockerfile

@@ -1,5 +1,5 @@
 # ============================================
-# Switchboard Core — Unified Dockerfile
+# Armature — Unified Dockerfile
 # ============================================
 # Stage 1: Build Go backend
 # Stage 2: Download JS vendor libs (marked, DOMPurify)
@@ -20,7 +20,7 @@ COPY server/go.mod server/go.sum* ./
 COPY server/ .
 COPY VERSION ./
 RUN go mod download && go mod tidy && go mod verify
-RUN CGO_ENABLED=0 go build -ldflags="-s -w -X main.Version=$(cat VERSION)" -o /bin/switchboard .
+RUN CGO_ENABLED=0 go build -ldflags="-s -w -X main.Version=$(cat VERSION)" -o /bin/armature .
 
 # ── Stage 2: Vendor JS libs ─────────────────
 FROM node:20-alpine AS vendor
@@ -70,7 +70,7 @@ FROM nginx:1-alpine
 RUN apk add --no-cache bash git
 
 # Go backend binary
-COPY --from=backend /bin/switchboard /usr/local/bin/switchboard
+COPY --from=backend /bin/armature /usr/local/bin/armature
 COPY --from=backend /app/database/migrations /app/database/migrations
 
 # Frontend static files