feat(phase-5): FastAPI 엔드포인트 (검색/차트/예측/메트릭/뉴스)

- GET  /api/symbols/search?q=...&seed_only=  : trigram + prefix + ILIKE 합산 정렬
- GET  /api/symbols/{code}                    : 메타
- GET  /api/chart/{code}?days=N&include_*     : OHLCV + 일별 감성 + 외인기관거래대금
- POST /api/predict/{code}?horizons=1,3,5     : on-demand 앙상블 예측 + DB 적재
                                                (user_triggered=TRUE)
- GET  /api/predict/{code}/latest             : 최신 base_date 의 예측 묶음 + base_close
                                                (UI 가 차트 마지막 점에 이어 붙임)
- GET  /api/metrics/{code}?window_days=N      : 종목 단위 hit_rate / mae (model, horizon 별)
- GET  /api/metrics?window_days=N             : 전체 누적
- GET  /api/news/{code}?source=&limit=        : 최신순 뉴스/공시 목록 (감성 점수 포함)

main.py 에 6개 라우터 모두 include.

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

backend/app/api/metrics.py

@@ -0,0 +1,101 @@
+"""모델 성능 메트릭 API."""
+from __future__ import annotations
+
+from datetime import date, timedelta
+
+from fastapi import APIRouter, HTTPException, Query
+from sqlalchemy import text
+
+from app.db.connection import get_engine
+
+router = APIRouter(prefix="/api/metrics", tags=["metrics"])
+
+
+@router.get("/{code}")
+def code_metrics(
+    code: str,
+    window_days: int = Query(default=30, ge=1, le=365),
+) -> dict:
+    """code 의 최근 window_days 윈도우 prediction_outcomes 집계."""
+    eng = get_engine()
+    end = date.today()
+    start = end - timedelta(days=window_days)
+    with eng.connect() as conn:
+        sym = conn.execute(
+            text("SELECT code, name FROM symbols WHERE code = :c"),
+            {"c": code},
+        ).first()
+        if not sym:
+            raise HTTPException(status_code=404, detail=f"unknown code: {code}")
+        rows = conn.execute(
+            text(
+                """
+                SELECT model, horizon,
+                       COUNT(*) AS n,
+                       AVG(CASE WHEN direction_hit THEN 1.0 ELSE 0.0 END) AS hit_rate,
+                       AVG(abs_error) AS mae
+                  FROM prediction_outcomes
+                 WHERE code = :c AND resolved_at >= :s
+                 GROUP BY model, horizon
+                 ORDER BY model, horizon
+                """
+            ),
+            {"c": code, "s": start},
+        ).all()
+
+    return {
+        "code": sym[0],
+        "name": sym[1],
+        "window_days": window_days,
+        "range": {"from": str(start), "to": str(end)},
+        "by_model_horizon": [
+            {
+                "model": r[0],
+                "horizon": int(r[1]),
+                "n": int(r[2]),
+                "hit_rate": float(r[3]) if r[3] is not None else None,
+                "mae": float(r[4]) if r[4] is not None else None,
+            }
+            for r in rows
+        ],
+    }
+
+
+@router.get("")
+def overall_metrics(
+    window_days: int = Query(default=30, ge=1, le=365),
+) -> dict:
+    """전체 시드 종목 누적 메트릭."""
+    eng = get_engine()
+    end = date.today()
+    start = end - timedelta(days=window_days)
+    with eng.connect() as conn:
+        rows = conn.execute(
+            text(
+                """
+                SELECT po.model, po.horizon,
+                       COUNT(*) AS n,
+                       AVG(CASE WHEN po.direction_hit THEN 1.0 ELSE 0.0 END) AS hit_rate,
+                       AVG(po.abs_error) AS mae
+                  FROM prediction_outcomes po
+                 WHERE po.resolved_at >= :s
+                 GROUP BY po.model, po.horizon
+                 ORDER BY po.model, po.horizon
+                """
+            ),
+            {"s": start},
+        ).all()
+    return {
+        "window_days": window_days,
+        "range": {"from": str(start), "to": str(end)},
+        "by_model_horizon": [
+            {
+                "model": r[0],
+                "horizon": int(r[1]),
+                "n": int(r[2]),
+                "hit_rate": float(r[3]) if r[3] is not None else None,
+                "mae": float(r[4]) if r[4] is not None else None,
+            }
+            for r in rows
+        ],
+    }