chore: B1 모노레포 스캐폴드 스켈레톤 (yakcloud-packages)

- pnpm+turbo workspace, tsconfig base, .npmrc(Gitea 레지스트리)
- 7 패키지 스텁(ds-sdk 리프 → ui/api-client type-only → client-shell/bff-kit; backup-core 신규)
  package.json 의존으로 DAG·역의존 금지 규칙 강제
- Apache-2.0 LICENSE + NOTICE/LOGO_ATTRIBUTION(벤더 상표 로고 미번들, URL-only)
- .gitea/workflows/ci.yml(build/typecheck/lint · bind-env-drift · secret-scan · standalone-smoke)
- scripts: bind-env-check(check-only 게이트) · standalone-smoke(lazy-require 불변식) 스켈레톤
- apps/ds-web standalone 데모 스텁

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

LICENSE

@@ -0,0 +1,20 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   [전체 Apache-2.0 본문은 https://www.apache.org/licenses/LICENSE-2.0.txt 에서
+    표준 텍스트로 채워 넣을 것 — 스캐폴드에는 헤더만 둔다.]
+
+   Copyright 2026 YakCloud
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.