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/predict.py

@@ -0,0 +1,137 @@
+"""예측 API.
+
+POST /api/predict/{code}                : on-demand 예측 + predictions 적재 (user_triggered=TRUE)
+GET  /api/predict/{code}/latest         : 가장 최근 base_date 의 예측 horizons 묶음 반환
+                                           (UI 가 새로고침해도 같은 결과 보여줄 때 사용)
+"""
+from __future__ import annotations
+
+import json
+import logging
+from datetime import datetime, timedelta, timezone
+
+from fastapi import APIRouter, HTTPException, Query
+from sqlalchemy import text
+
+from app.db.connection import get_engine
+from app.pipelines.predict_one import predict_and_store
+
+logger = logging.getLogger(__name__)
+KST = timezone(timedelta(hours=9))
+
+router = APIRouter(prefix="/api/predict", tags=["predict"])
+
+
+@router.post("/{code}")
+def predict_endpoint(
+    code: str,
+    horizons: str = Query(default="1,3,5", description="쉼표 구분 정수. ex) '1,3,5'"),
+    user_triggered: bool = Query(default=True),
+) -> dict:
+    """on-demand 예측. UI 의 '예상차트 보기' 클릭이 호출."""
+    eng = get_engine()
+    with eng.connect() as conn:
+        row = conn.execute(
+            text("SELECT code, name FROM symbols WHERE code = :c"),
+            {"c": code},
+        ).first()
+    if not row:
+        raise HTTPException(status_code=404, detail=f"unknown code: {code}")
+
+    try:
+        hs = tuple(int(x) for x in horizons.split(",") if x.strip())
+        if not hs or any(h < 1 or h > 30 for h in hs):
+            raise ValueError("invalid horizons")
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=f"bad horizons: {exc}")
+
+    try:
+        result = predict_and_store(code, horizons=hs, user_triggered=user_triggered)
+    except RuntimeError as exc:
+        raise HTTPException(status_code=409, detail=str(exc))
+    except Exception as exc:  # noqa: BLE001
+        logger.exception("predict_and_store failed for %s", code)
+        raise HTTPException(status_code=500, detail=str(exc))
+
+    return result
+
+
+@router.get("/{code}/latest")
+def latest_prediction(code: str) -> dict:
+    """가장 최근 base_date 에 대한 'ensemble' 예측 묶음."""
+    eng = get_engine()
+    with eng.connect() as conn:
+        symbol = conn.execute(
+            text("SELECT code, name FROM symbols WHERE code = :c"),
+            {"c": code},
+        ).first()
+        if not symbol:
+            raise HTTPException(status_code=404, detail=f"unknown code: {code}")
+
+        latest_base = conn.execute(
+            text(
+                "SELECT MAX(base_date) FROM predictions "
+                "WHERE code = :c AND model = 'ensemble'"
+            ),
+            {"c": code},
+        ).first()
+        if not latest_base or latest_base[0] is None:
+            return {"code": code, "found": False, "steps": []}
+        base_date = latest_base[0]
+
+        rows = conn.execute(
+            text(
+                """
+                SELECT predicted_at, target_date, horizon, direction,
+                       prob_up, prob_flat, prob_down, expected_return,
+                       point_forecast, ci_low, ci_high, user_triggered,
+                       features_snapshot
+                  FROM predictions
+                 WHERE code = :c AND base_date = :bd AND model = 'ensemble'
+                 ORDER BY horizon
+                """
+            ),
+            {"c": code, "bd": base_date},
+        ).all()
+
+        # base_close (그 날 ohlcv) 도 같이 반환 — UI 가 차트 마지막 점에 이어붙일 때 사용
+        base_close_row = conn.execute(
+            text("SELECT close FROM ohlcv_daily WHERE code = :c AND date = :d"),
+            {"c": code, "d": base_date},
+        ).first()
+        base_close = float(base_close_row[0]) if base_close_row and base_close_row[0] is not None else None
+
+    steps = []
+    for r in rows:
+        feats = r[12]
+        if isinstance(feats, str):
+            try:
+                feats = json.loads(feats)
+            except Exception:  # noqa: BLE001
+                pass
+        steps.append(
+            {
+                "predicted_at": r[0].isoformat() if r[0] else None,
+                "target_date": str(r[1]),
+                "horizon": int(r[2]),
+                "direction": r[3],
+                "prob_up": float(r[4]) if r[4] is not None else None,
+                "prob_flat": float(r[5]) if r[5] is not None else None,
+                "prob_down": float(r[6]) if r[6] is not None else None,
+                "expected_return": float(r[7]) if r[7] is not None else None,
+                "point_close": float(r[8]) if r[8] is not None else None,
+                "ci_low": float(r[9]) if r[9] is not None else None,
+                "ci_high": float(r[10]) if r[10] is not None else None,
+                "user_triggered": bool(r[11]),
+                "features_snapshot": feats,
+            }
+        )
+
+    return {
+        "code": symbol[0],
+        "name": symbol[1],
+        "found": True,
+        "base_date": str(base_date),
+        "base_close": base_close,
+        "steps": steps,
+    }