refactor: rename stock-lab → stock (graduation)

- git mv stock-lab/ → stock/
- docker-compose.yml: 서비스 키 + container_name + build.context +
  frontend.depends_on + agent-office STOCK_LAB_URL → STOCK_URL
- agent-office/app: config.py, service_proxy.py, agents/stock.py, tests/
  STOCK_LAB_URL → STOCK_URL
- nginx/default.conf: proxy_pass http://stock-lab → http://stock (3 lines)
- CLAUDE.md / README.md / STATUS.md / scripts/ 문구 갱신
- stock/ 내부 자기 참조 갱신

lab 네이밍 정책 (feedback_lab_naming.md) graduation.
API URL / Python import / DB 파일명 변경 없음.

scripts/deploy-nas.sh

@@ -2,7 +2,7 @@
 set -euo pipefail
 
 # ── 서비스 목록 (한 곳에서만 관리) ──
-SERVICES="lotto travel-proxy deployer stock-lab music-lab blog-lab realestate-lab agent-office personal packs-lab nginx scripts"
+SERVICES="lotto travel-proxy deployer stock music-lab blog-lab realestate-lab agent-office personal packs-lab nginx scripts"
 
 # 1. 자동 감지: Docker 컨테이너 내부인가?
 if [ -d "/repo" ] && [ -d "/runtime" ]; then