fix: use tenant.code as realm name, remove keycloak_realm fallback

realm = tenant.code (管理中心容器命名統一以 code 為依據)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/services/scheduler/schedule_tenant.py

@@ -201,7 +201,7 @@ def _generate_tenant_route_yaml(tenant, is_active: bool) -> str:
 
     if tenant.is_manager:
         # Manager 租戶：/admin → vmis-backend，/api → vmis-backend，根路徑 → NC Drive
-        realm = tenant.keycloak_realm or tenant.code
+        realm = tenant.code
         vmis_backend_url = f"http://{realm}:10281" if is_active else f"http://{realm}-test:10281"
         lines += [
             "  middlewares:",
@@ -859,7 +859,7 @@ def run_tenant_check(schedule_log_id: int, db: Session):
     admin_emails = _get_admin_emails(db)
 
     for tenant in tenants:
-        realm = tenant.keycloak_realm or tenant.code
+        realm = tenant.code
         is_active = tenant.status == "active"
 
         nc_name = f"nc-{tenant.code}" if is_active else f"nc-{tenant.code}-test"