add retroactive check for yesterday's missed habits on /today

Users often only realize a habit was missed the next day; a same-day-only
check made it impossible to record it after the fact.

app/routers/pages.py

@@ -51,6 +51,7 @@ def _today_context(db: Session, user_id: int, **extra) -> dict:
     return {
         "build_items": build_items,
         "quit_items": quit_items,
+        "yesterday_missed": log_service.get_yesterday_missed_items(db, user_id),
         "total_count": len(all_items),
         "checked_count": sum(1 for item in all_items if item.checked),
         **extra,
@@ -89,6 +90,26 @@ def toggle_today_page(request: Request, habit_id: int, db: Session = Depends(get
     )
 
 
+@router.post("/today/{habit_id}/toggle-yesterday")
+def toggle_yesterday_page(request: Request, habit_id: int, db: Session = Depends(get_db)):
+    current = _current_user_or_redirect(request, db)
+    if isinstance(current, RedirectResponse):
+        return current
+
+    habit = habit_service.get_habit(db, habit_id, current.id)
+    if habit is None:
+        return Response(status_code=404)
+
+    yesterday = date.today() - timedelta(days=1)
+    _, milestone_streak = log_service.toggle_check_and_celebrate(db, habit, yesterday)
+    extra = {"celebrate_habit_name": habit.name, "celebrate_streak": milestone_streak} if milestone_streak else {}
+    return templates.TemplateResponse(
+        request,
+        "partials/today_content.html",
+        {"logged_in": True, "current_user": current, **_today_context(db, current.id, **extra)},
+    )
+
+
 @router.get("/habits")
 def habits_page(request: Request, tab: str = "build", db: Session = Depends(get_db)):
     current = _current_user_or_redirect(request, db)

app/services/log_service.py

@@ -50,6 +50,13 @@ def get_today_items(db: Session, user_id: int, target_date: date) -> tuple[list[
     return build_items, quit_items
 
 
+def get_yesterday_missed_items(db: Session, user_id: int) -> list[TodayItem]:
+    """어제 예정되어 있었지만 아직 체크하지 않은 습관 목록 (형성+중단 합쳐서, /today 화면의 소급 체크용)."""
+    yesterday = date.today() - timedelta(days=1)
+    build_items, quit_items = get_today_items(db, user_id, yesterday)
+    return [item for item in build_items + quit_items if not item.checked]
+
+
 def toggle_check(db: Session, habit_id: int, log_date: date) -> bool:
     """체크 상태를 반전시키고 토글 후의 체크 여부를 반환한다.
 

app/templates/partials/today_content.html

@@ -24,6 +24,15 @@
   </div>
 </div>
 
+{% if yesterday_missed %}
+<h2>어제 놓친 습관</h2>
+<div class="card">
+  {% for item in yesterday_missed %}
+    {% include "partials/yesterday_item.html" %}
+  {% endfor %}
+</div>
+{% endif %}
+
 <h2>형성 습관</h2>
 <div class="card">
   {% for item in build_items %}

app/templates/partials/yesterday_item.html

@@ -0,0 +1,16 @@
+<div class="habit-item">
+  <div class="habit-item-main">
+    <button
+      type="button"
+      class="check-indicator"
+      hx-post="/today/{{ item.habit_id }}/toggle-yesterday"
+      hx-target="#today-content"
+      hx-swap="innerHTML"
+      aria-label="{{ item.name }} 어제 체크"
+    ></button>
+    <div>
+      <div class="habit-item-name">{{ item.name }}</div>
+      {% if item.condition_text %}<div class="habit-item-condition">{{ item.condition_text }}</div>{% endif %}
+    </div>
+  </div>
+</div>

tests/test_log_service.py

@@ -123,6 +123,33 @@ def test_get_today_items_excludes_habits_not_scheduled_today(db_session, test_us
     assert quit_items == []
 
 
+# ---- get_yesterday_missed_items ----
+
+
+def test_get_yesterday_missed_items_includes_unchecked_scheduled_habit(db_session, test_user):
+    habit = _make_habit(db_session, test_user.id, name="어제 놓친 습관")
+
+    missed = log_service.get_yesterday_missed_items(db_session, test_user.id)
+    assert [item.habit_id for item in missed] == [habit.id]
+
+
+def test_get_yesterday_missed_items_excludes_already_checked(db_session, test_user):
+    habit = _make_habit(db_session, test_user.id)
+    _check(db_session, habit.id, date.today() - timedelta(days=1))
+
+    missed = log_service.get_yesterday_missed_items(db_session, test_user.id)
+    assert missed == []
+
+
+def test_get_yesterday_missed_items_excludes_habits_not_scheduled_yesterday(db_session, test_user):
+    yesterday = date.today() - timedelta(days=1)
+    other_day_mask = 1 << ((yesterday.weekday() + 1) % 7)  # 어제가 아닌 요일 하나만 선택
+    _make_habit(db_session, test_user.id, weekdays_mask=other_day_mask)
+
+    missed = log_service.get_yesterday_missed_items(db_session, test_user.id)
+    assert missed == []
+
+
 # ---- get_habit_stats: completion_rate ----
 
 

tests/test_pages_today.py

@@ -1,4 +1,7 @@
+from datetime import date, timedelta
+
 from app.models.habit import ALL_WEEKDAYS_MASK, HabitType
+from app.models.habit_log import HabitLog
 from app.schemas.habit import HabitCreate
 from app.services import habit_service
 
@@ -38,3 +41,31 @@ def test_toggle_today_page_for_other_users_habit_returns_404(auth_client, db_ses
 
     response = auth_client.post(f"/today/{others_habit.id}/toggle")
     assert response.status_code == 404
+
+
+def test_today_page_shows_yesterday_missed_habit(auth_client, db_session, test_user):
+    _make_habit(db_session, test_user.id, name="어제 놓친 습관")
+
+    response = auth_client.get("/today")
+    assert response.status_code == 200
+    assert "어제 놓친 습관" in response.text
+
+
+def test_toggle_yesterday_page_creates_log_for_yesterday(auth_client, db_session, test_user):
+    habit = _make_habit(db_session, test_user.id, name="어제 습관")
+
+    response = auth_client.post(f"/today/{habit.id}/toggle-yesterday")
+    assert response.status_code == 200
+
+    yesterday = date.today() - timedelta(days=1)
+    log = db_session.query(HabitLog).filter_by(habit_id=habit.id, log_date=yesterday).one()
+    assert log is not None
+    # 체크되었으니 더 이상 "어제 놓친 습관" 목록에 나오지 않아야 한다.
+    assert "어제 놓친 습관" not in response.text
+
+
+def test_toggle_yesterday_page_for_other_users_habit_returns_404(auth_client, db_session, other_user):
+    others_habit = _make_habit(db_session, other_user.id, name="남의 습관")
+
+    response = auth_client.post(f"/today/{others_habit.id}/toggle-yesterday")
+    assert response.status_code == 404