Phase 1: warp_engine gem skeleton (path gem, mounted engine)

- libs/ruby/warp_engine: gemspec, WarpEngine::Engine (isolate_namespace with
  empty table_name_prefix), WarpEngine.configure surface (container paths,
  update_secret, image_owners), empty engine routes
- host Gemfile: path gem; host routes: mount WarpEngine::Engine => "/" as
  the last entry so host routes always win
- docker: api build context moved to repo root so libs/ is visible at
  bundle-install time; ./libs:/libs runtime mount; root .dockerignore to keep
  data/ and node_modules out of the build context

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docker-compose.yaml

@@ -144,8 +144,9 @@ services:
 
   api:
     build:
-      context: ./apps/api
-      dockerfile: Dockerfile.development
+      # Repo-gyökér context: a libs/ alatti path gemeknek látszaniuk kell build közben
+      context: .
+      dockerfile: apps/api/Dockerfile.development
     container_name: api
     environment:
       - RAILS_ENV=development
@@ -168,6 +169,7 @@ services:
       - ./data/softwares:/softwares
       - ./data/images:/images
       - ./apps/api:/app
+      - ./libs:/libs
       - api_bundle:/usr/local/bundle
     labels:
       - "traefik.enable=true"