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>

server/handlers/test_helpers_test.go

@@ -13,7 +13,7 @@ import (
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/google/uuid"
 
-	"switchboard-core/database"
+	"armature/database"
 )
 
 const testJWTSecret = "test-secret-key-for-handler-tests"
@@ -48,7 +48,7 @@ func makeToken(userID, email, _ string) string {
 		RegisteredClaims: jwt.RegisteredClaims{
 			IssuedAt:  jwt.NewNumericDate(time.Now()),
 			ExpiresAt: jwt.NewNumericDate(time.Now().Add(15 * time.Minute)),
-			Issuer:    "switchboard-core",
+			Issuer:    "armature",
 		},
 	}
 	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)