feat(stats): 일별 방문자 집계 추가

page_visits 테이블((visit_date, device_id) 유니크) — 하루 1기기 1회 집계.
POST /api/visit(접속 기록), GET /api/admin/visits(일별 순수 방문자, Bearer).
프론트는 App 마운트 시 1회 recordVisit() 호출.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/app/main.py

@@ -13,7 +13,7 @@ from fastapi.middleware.cors import CORSMiddleware
 
 from .config import settings
 from .database import init_db
-from .routers import admin, leaderboard, matches, predictions
+from .routers import admin, leaderboard, matches, predictions, visits
 from .scoring import load_scoring_data
 from .seed import seed_if_empty
 
@@ -44,6 +44,7 @@ app.include_router(matches.router)
 app.include_router(predictions.router)
 app.include_router(leaderboard.router)
 app.include_router(admin.router)
+app.include_router(visits.router)
 
 
 @app.get("/api/health")

backend/app/models.py

@@ -9,10 +9,11 @@
 """
 from __future__ import annotations
 
-from datetime import datetime
+from datetime import date, datetime
 
 from sqlalchemy import (
     Boolean,
+    Date,
     DateTime,
     ForeignKey,
     Integer,
@@ -178,3 +179,22 @@ class UserPoints(Base):
     updated_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), server_default=func.now(), onupdate=func.now()
     )
+
+
+class PageVisit(Base):
+    """페이지 방문 — 하루(KST)에 같은 기기(device_id)는 1회만 기록(순수 방문자 수).
+
+    일별 집계 = visit_date 로 GROUP BY COUNT. 같은 날 재방문은 유니크 제약으로 무시.
+    """
+
+    __tablename__ = "page_visits"
+    __table_args__ = (
+        UniqueConstraint("visit_date", "device_id", name="uq_visit_date_device"),
+    )
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+    visit_date: Mapped[date] = mapped_column(Date, index=True)  # KST 기준 날짜
+    device_id: Mapped[str] = mapped_column(String)  # 비로그인 식별 (localStorage uuid)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now()
+    )

backend/app/routers/admin.py

@@ -2,14 +2,14 @@
 from __future__ import annotations
 
 from fastapi import APIRouter, Depends, Header, HTTPException
-from sqlalchemy import select
+from sqlalchemy import func, select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from ..config import settings
 from ..database import get_db
 from ..domain import now_utc
-from ..models import AIPrediction, Match
-from ..schemas import AdminAIPredictionIn, AdminSetResultIn, GenericOk
+from ..models import AIPrediction, Match, PageVisit
+from ..schemas import AdminAIPredictionIn, AdminSetResultIn, DailyVisitOut, GenericOk
 from ..services.grading import apply_result
 
 router = APIRouter(prefix="/api/admin", tags=["admin"])
@@ -70,3 +70,18 @@ async def set_result(
         detail="result set & graded",
         extra={"gradedPicks": graded, "emailsSentBy": "worker"},
     )
+
+
+@router.get(
+    "/visits", response_model=list[DailyVisitOut], dependencies=[Depends(require_admin)]
+)
+async def daily_visits(db: AsyncSession = Depends(get_db)) -> list[DailyVisitOut]:
+    """일별 순수 방문자 수 (최신순)."""
+    rows = (
+        await db.execute(
+            select(PageVisit.visit_date, func.count())
+            .group_by(PageVisit.visit_date)
+            .order_by(PageVisit.visit_date.desc())
+        )
+    ).all()
+    return [DailyVisitOut(date=d.isoformat(), uniqueVisitors=c) for d, c in rows]

backend/app/routers/visits.py

@@ -0,0 +1,26 @@
+"""방문자 집계 — 페이지 접속 기록(일별 순수 방문자)."""
+from __future__ import annotations
+
+from fastapi import APIRouter, Depends
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from ..database import get_db
+from ..domain import KST, now_utc
+from ..models import PageVisit
+from ..schemas import VisitIn, VisitOut
+
+router = APIRouter(prefix="/api/visit", tags=["visits"])
+
+
+@router.post("", response_model=VisitOut)
+async def record_visit(body: VisitIn, db: AsyncSession = Depends(get_db)) -> VisitOut:
+    """페이지 접속 기록. 같은 기기가 같은 날(KST) 재접속하면 집계하지 않는다."""
+    today = now_utc().astimezone(KST).date()
+    db.add(PageVisit(visit_date=today, device_id=body.deviceId))
+    try:
+        await db.commit()
+        return VisitOut(ok=True, counted=True)  # 오늘 첫 방문 → 집계
+    except IntegrityError:
+        await db.rollback()
+        return VisitOut(ok=True, counted=False)  # 재방문 → 무시

backend/app/schemas.py

@@ -125,3 +125,18 @@ class GenericOk(BaseModel):
     ok: bool
     detail: str = ""
     extra: dict | None = None
+
+
+# ── 방문자 집계 ─────────────────────────────────────────────
+class VisitIn(BaseModel):
+    deviceId: str = Field(min_length=8, max_length=64)
+
+
+class VisitOut(BaseModel):
+    ok: bool
+    counted: bool  # 오늘 첫 방문이면 True(집계됨), 재방문이면 False
+
+
+class DailyVisitOut(BaseModel):
+    date: str  # YYYY-MM-DD (KST)
+    uniqueVisitors: int

frontend/src/App.tsx

@@ -1,10 +1,17 @@
+import { useEffect } from "react";
 import { Routes, Route } from "react-router-dom";
 import Dashboard from "./pages/Dashboard";
 import MatchDetail from "./pages/MatchDetail";
 import Leaderboard from "./pages/Leaderboard";
 import NotFound from "./pages/NotFound";
+import { recordVisit } from "./lib/api";
 
 export default function App() {
+  // 접속 시 1회 방문 기록 (하루 1기기 1회 집계는 백엔드가 처리)
+  useEffect(() => {
+    recordVisit();
+  }, []);
+
   return (
     <Routes>
       <Route path="/" element={<Dashboard />} />

frontend/src/lib/api.ts

@@ -66,6 +66,14 @@ export function getLeaderboard(): Promise<Leaderboard> {
   return http<Leaderboard>(`/leaderboard`);
 }
 
+// 방문 기록 (하루 1기기 1회 집계). 실패는 무시(fire-and-forget).
+export function recordVisit(): void {
+  void http(`/visit`, {
+    method: "POST",
+    body: JSON.stringify({ deviceId: getDeviceId() }),
+  }).catch(() => {});
+}
+
 // ── 비로그인 식별: deviceId (localStorage 영속) ──
 const DEVICE_KEY = "tp_device_id";
 export function getDeviceId(): string {