Add a team attendance KPI panel and no-show check-in tracking

Team pages now show, for the selected season: overall attendance rate,
best/worst attenders, players who missed the last 2 practices, and
no-shows (an affirmative RSVP checked in as absent). No-shows need a
real distinction the RSVP status alone can't make, so Attendance gains
a separate showed_up tri-state field, usable today via Django admin --
a full check-in screen is future work for the coaches app.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R1gj3J1QPfP38XWpnpbFpy

events/services/attendance.py

@@ -6,10 +6,11 @@ The audience of an event is the union of the current rosters of its ``teams``
 for events that are still in the future — history is never rewritten.
 """
 
+from django.db.models import Count, Q
 from django.utils import timezone
 
 from club.models import Season
-from events.models import Attendance
+from events.models import Attendance, Event
 from members.models import Member
 from teams.models import TeamMembership
 
@@ -57,3 +58,85 @@ def sync_event_attendances(event):
     to_remove = existing_ids - desired_ids
     if to_remove:
         event.attendances.filter(member_id__in=to_remove).delete()
+
+
+def record_check_in(attendance, *, showed_up):
+    """Record whether ``attendance``'s member actually showed up, separate from
+    their RSVP status -- the hook a future check-in UI (the coaches app) writes
+    through. Nothing in this codebase calls this yet; it exists so a no-show can
+    be recorded the moment something does."""
+    attendance.showed_up = showed_up
+    attendance.save(update_fields=["showed_up"])
+
+
+def team_attendance_rate(team, season):
+    """Turnout for ``team`` in ``season``: present / (present + absent) among
+    past events -- same definition as
+    controlpanel.services.statistics.attendance_rates, just scoped to one team
+    instead of the whole club."""
+    counts = Attendance.objects.filter(event__teams=team, event__season=season, event__start__lt=timezone.now()).aggregate(
+        present=Count("id", filter=Q(status=Attendance.AttendanceStatus.PRESENT)),
+        absent=Count("id", filter=Q(status=Attendance.AttendanceStatus.ABSENT)),
+    )
+    answered = counts["present"] + counts["absent"]
+    return round(100 * counts["present"] / answered) if answered else None
+
+
+def player_attendance_rankings(team, season, *, minimum_responses=3):
+    """Each player's turnout this season, best first:
+    ``[{"member": Member, "rate": int, "responses": int}, ...]``. Excludes
+    anyone with fewer than ``minimum_responses`` present/absent replies -- one
+    absence out of one invite would otherwise read as "0%, worst on the team."
+    """
+    rows = (
+        Attendance.objects.filter(
+            event__teams=team,
+            event__season=season,
+            event__start__lt=timezone.now(),
+            status__in=[Attendance.AttendanceStatus.PRESENT, Attendance.AttendanceStatus.ABSENT],
+        )
+        .values("member")
+        .annotate(present=Count("id", filter=Q(status=Attendance.AttendanceStatus.PRESENT)), responses=Count("id"))
+        .filter(responses__gte=minimum_responses)
+    )
+
+    members_by_id = Member.objects.in_bulk([row["member"] for row in rows])
+    rankings = [{"member": members_by_id[row["member"]], "rate": round(100 * row["present"] / row["responses"]), "responses": row["responses"]} for row in rows]
+    rankings.sort(key=lambda entry: entry["rate"], reverse=True)
+    return rankings
+
+
+def players_who_missed_recent_practices(team, season, *, count=2):
+    """Members absent or silent (not excused) on *every one* of the team's
+    ``count`` most recent past training-kind events this season. Empty if the
+    team has fewer than ``count`` past practices logged yet -- not enough
+    history to call anyone out."""
+    practices = list(Event.objects.filter(teams=team, season=season, kind=Event.EventKind.TRAINING, start__lt=timezone.now()).order_by("-start")[:count])
+    if len(practices) < count:
+        return Member.objects.none()
+
+    flagged = (Attendance.AttendanceStatus.ABSENT, Attendance.AttendanceStatus.NO_RESPONSE)
+    missed_by_member = None
+    for practice in practices:
+        missed_here = set(Attendance.objects.filter(event=practice, status__in=flagged).values_list("member_id", flat=True))
+        missed_by_member = missed_here if missed_by_member is None else missed_by_member & missed_here
+
+    return Member.objects.filter(pk__in=missed_by_member).order_by("last_name", "first_name")
+
+
+def team_no_shows(team, season):
+    """Attendance rows where the member RSVPed present/selected but was
+    checked in as showed_up=False -- most recent first. Each entry carries
+    both the member and the event: a no-show is about a specific missed
+    occasion, not a season-long rate. Never inferred from a missing check-in --
+    with nothing checking anyone in yet, that would flag every "present" RSVP."""
+    return (
+        Attendance.objects.filter(
+            event__teams=team,
+            event__season=season,
+            status__in=[Attendance.AttendanceStatus.PRESENT, Attendance.AttendanceStatus.SELECTED],
+            showed_up=False,
+        )
+        .select_related("member", "event")
+        .order_by("-event__start")
+    )