feat(phase-1a): external data fetchers + refresh pipeline + scheduler

10종목 시드 + pykrx OHLCV / 외인·기관 거래대금, KIS read-only EOD, OpenDART
공시, 네이버 금융 뉴스 스크레이퍼, 구글 뉴스 RSS, yfinance 거시(KOSPI/KOSDAQ/
USDKRW/US10Y) fetcher 를 추가하고 refresh_one / daily_batch / backfill /
APScheduler(16:00 KST) 파이프라인으로 묶음.

- backend/app/seed: 10종목 시드 (대형/고변동/테마/플랫폼/방어)
- backend/app/fetch: pykrx, kis, dart, news, macro, symbols_seed
- backend/app/pipelines: refresh_one, daily_batch, backfill(CLI), scheduler
- backend/app/api/refresh.py: POST /api/refresh/{code}?lookback_days=N
- backend/app/main.py: lifespan 으로 스케줄러 기동/종료, /health/keys 추가
- README: .env 복사 안내 보강

스모크 테스트 (실제 키 사용) 결과:
  KIS token  : ok (token 346자 발급)
  KIS daily  : 005930 11rows
  DART list  : 005930 30일 10건
  Naver news : 005930 12건
  Google RSS : "삼성전자" 92건

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/app/fetch/macro.py

@@ -0,0 +1,83 @@
+"""거시/지수 지표: yfinance 로 KOSPI / KOSDAQ / USDKRW / US10Y."""
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass
+from datetime import date, timedelta
+
+from sqlalchemy import text
+
+from app.db.connection import get_engine
+
+logger = logging.getLogger(__name__)
+
+# yfinance ticker -> macro_daily.key
+TICKER_MAP: dict[str, str] = {
+    "^KS11": "kospi",
+    "^KQ11": "kosdaq",
+    "KRW=X": "usdkrw",
+    "^TNX": "us10y",
+}
+
+
+@dataclass
+class MacroResult:
+    key: str
+    inserted: int
+    updated: int
+    error: str | None = None
+
+    def status(self) -> str:
+        return "failed" if self.error else "ok"
+
+
+def fetch_macro_daily(*, years: int = 5) -> list[MacroResult]:
+    end = date.today()
+    start = end - timedelta(days=365 * years)
+    try:
+        import yfinance as yf
+    except Exception as exc:  # noqa: BLE001
+        return [MacroResult(key="*", inserted=0, updated=0, error=f"yfinance import failed: {exc}")]
+
+    results: list[MacroResult] = []
+    engine = get_engine()
+    for ticker, key in TICKER_MAP.items():
+        try:
+            df = yf.download(ticker, start=start.isoformat(), end=(end + timedelta(days=1)).isoformat(),
+                             progress=False, auto_adjust=False)
+        except Exception as exc:  # noqa: BLE001
+            logger.exception("yfinance failed ticker=%s", ticker)
+            results.append(MacroResult(key=key, inserted=0, updated=0, error=str(exc)))
+            continue
+        if df is None or df.empty:
+            results.append(MacroResult(key=key, inserted=0, updated=0, error="empty"))
+            continue
+        # Close 컬럼만 사용
+        close_col = "Close" if "Close" in df.columns else df.columns[0]
+        ins = upd = 0
+        with engine.begin() as conn:
+            for idx, row in df.iterrows():
+                day = idx.date() if hasattr(idx, "date") else date.fromisoformat(str(idx)[:10])
+                val = row[close_col]
+                try:
+                    val_f = float(val.iloc[0] if hasattr(val, "iloc") else val)
+                except Exception:  # noqa: BLE001
+                    continue
+                res = conn.execute(
+                    text(
+                        """
+                        INSERT INTO macro_daily (date, key, value)
+                        VALUES (:date, :key, :value)
+                        ON CONFLICT (date, key) DO UPDATE SET value = EXCLUDED.value
+                        RETURNING (xmax = 0) AS inserted
+                        """
+                    ),
+                    {"date": day, "key": key, "value": val_f},
+                )
+                r = res.first()
+                if r and r[0]:
+                    ins += 1
+                else:
+                    upd += 1
+        results.append(MacroResult(key=key, inserted=ins, updated=upd))
+    return results