Phase 6: polish — apipie matcher, install generator, engine migrations, docs

- host apipie matcher now globs the engine controllers, so /api/docs and
  /api/swagger keep documenting the catalog endpoints
- rails g warp_engine:install: initializer template + a clean
  create_warp_engine_tables migration (signed bigint PKs) for new hosts;
  TTG never runs it
- engine append_migrations initializer: future catalog migrations in the
  engine's db/migrate run via the host's rails db:migrate
- README documents the updater contract, config surface, host expectations
  (admin JS picker, apipie matcher) and the soft-delete/resurrection behavior
- make api-test runs both suites plus a production zeitwerk:check

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

Makefile

@@ -18,3 +18,9 @@ stop:
 	$(call docker_compose,down --remove-orphans)
 
 restart: stop start
+
+# Teljes API-teszt: host suite + warp_engine suite + production eager-load check
+api-test:
+	docker exec -e RAILS_ENV=test api bundle exec rspec
+	docker exec -w /libs/ruby/warp_engine -e RAILS_ENV=test api bundle exec rspec
+	docker exec -e RAILS_ENV=production -e SECRET_KEY_BASE=zeitwerkcheck api bundle exec rails zeitwerk:check