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.

stock/app/test_screener_nodes_momentum.py

@@ -0,0 +1,24 @@
+import datetime as dt
+import pandas as pd
+
+from app.screener.engine import ScreenContext
+from app.screener.nodes.momentum import Momentum20
+from app.screener._test_fixtures import make_master, make_prices, make_flow
+
+
+def _ctx(master, prices, flow):
+    return ScreenContext(master=master, prices=prices, flow=flow,
+                         kospi=pd.Series(dtype=float, name="kospi"),
+                         asof=dt.date(2026, 5, 12))
+
+
+def test_higher_momentum_gets_higher_score():
+    asof = dt.date(2026, 5, 12)
+    master = make_master(["UP", "DN"])
+    up = make_prices(["UP"], days=30, asof=asof, trend_pct=0.5)
+    dn = make_prices(["DN"], days=30, asof=asof, trend_pct=-0.3)
+    prices = pd.concat([up, dn], ignore_index=True)
+    flow = make_flow(["UP", "DN"], days=30, asof=asof)
+
+    out = Momentum20().compute(_ctx(master, prices, flow), {"window_days": 20})
+    assert out["UP"] > out["DN"]