feat: enforce the adapter barrel boundary in the architecture gate

그룹 바깥에서 어댑터 내부 파일을 직접 import하면 check:architecture가
거부한다. 회귀 fixture 2개가 거부와 허용을 각각 고정한다 — 규칙 이름을
바꿔 보면 fixture 검사가 먼저 깨지는 것을 확인했다.

도착점 정규식은 중첩 수량자 대신 교대를 쓴다. dependency-cruiser의 안전
정규식 검사가 (?:[^/]+/)? 안의 + 를 unsafe로 거부하기 때문이다.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/fixtures/architecture/dependency-graph/barrel/adapters/http/client.ts

@@ -0,0 +1,3 @@
+export function createFixtureHttpClient(): string {
+  return "fixture";
+}

tests/fixtures/architecture/dependency-graph/barrel/adapters/http/index.ts

@@ -0,0 +1 @@
+export { createFixtureHttpClient } from "./client.ts";

tests/fixtures/architecture/dependency-graph/barrel/bootstrap/compose-barrel.ts

@@ -0,0 +1,3 @@
+import { createFixtureHttpClient } from "../adapters/http/index.ts";
+
+export const barrelComposition = createFixtureHttpClient;

tests/fixtures/architecture/dependency-graph/barrel/bootstrap/compose-deep.ts

@@ -0,0 +1,3 @@
+import { createFixtureHttpClient } from "../adapters/http/client.ts";
+
+export const deepComposition = createFixtureHttpClient;