Simplify the line-up to yes/no picks, and stop truncating notifications

Coach mode's line-up screen no longer has lines/slots -- just a yes/no
toggle per available roster player, grouped by their roster position, both
in coach mode and on the published member-side view. Replaces LineupUnit/
LineupSlot with a single LineupSelection model.

Notifications now show their full body text (no more truncatechars) and the
unread colour bar spans the full row height via self-stretch, matching the
calendar row's own marker, so it still reads correctly once a body wraps to
several lines.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ECGMEwrc2k4D8VQuwjstj9

events/services/lineup.py

@@ -1,53 +1,46 @@
-"""Placing players into a Lineup's slots and publishing it -- coach mode's C3
-screen (mobile/coach_views.py's CoachLineupView/CoachLineupPlaceView). Mirrors
-events.services.attendance's shape: small, focused functions the view writes
-through rather than touching the models directly.
+"""Picking players for a Lineup (plain yes/no, no lines/slots) and publishing
+it -- coach mode's C3 screen (mobile/coach_views.py's CoachLineupView).
+Mirrors events.services.attendance's shape: small, focused functions the
+view writes through rather than touching the models directly.
 """
 
 from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 
 from club.services.access import event_season
-from events.models import Attendance, LineupSlot
+from events.models import Attendance, LineupSelection
 from members.models import Member
 from notifications.services import notify_members
-from teams.models import StaffAssignment
+from teams.models import StaffAssignment, TeamMembership
 
 #: Attendance statuses that mean "not actually available" -- these members
 #: stay exactly as they are on publish, never flipped to NOT_SELECTED, and
-#: aren't offered as placeable in the available-players pool.
+#: aren't offered as pickable for the line-up.
 UNAVAILABLE_STATUSES = [Attendance.AttendanceStatus.ABSENT, Attendance.AttendanceStatus.EXCUSED, Attendance.AttendanceStatus.NO_RESPONSE]
 
 
-def place_member(lineup, slot, member):
-    """Tap-to-place: ``member`` moves into ``slot``, vacating any other slot
-    of theirs in the same ``lineup`` first (a member is only ever in one slot
-    at a time). Whoever was already in ``slot``, if anyone, is simply bumped
-    back to the available pool -- the tap equivalent of the mock's "slots
-    accept one player and swap on drop", without true drag-and-drop's two-way
-    swap (see LineupSlot's own docstring for why tap-to-place instead of
-    drag-and-drop at all)."""
-    LineupSlot.objects.filter(unit__lineup=lineup, member=member).exclude(pk=slot.pk).update(member=None)
-    slot.member = member
-    slot.save(update_fields=["member"])
-
-
-def clear_slot(slot):
-    slot.member = None
-    slot.save(update_fields=["member"])
+def toggle_selection(lineup, member) -> bool:
+    """Flips ``member``'s yes/no pick for ``lineup`` -- deletes their row if
+    they were in, creates one if they weren't. Returns the new state (True =
+    now selected)."""
+    deleted, _details = LineupSelection.objects.filter(lineup=lineup, member=member).delete()
+    if deleted:
+        return False
+    LineupSelection.objects.create(lineup=lineup, member=member)
+    return True
 
 
 def publish_lineup(lineup):
     """Marks the lineup published and writes it into the game record via
     Attendance -- the reason AttendanceStatus.SELECTED/NOT_SELECTED exist,
-    previously unused anywhere. Every slotted member becomes SELECTED; every
+    previously unused anywhere. Every selected member becomes SELECTED; every
     other member with an Attendance row for this event who was actually
     available (not out/silent, see UNAVAILABLE_STATUSES) becomes
     NOT_SELECTED. Notifies only the selected players."""
     lineup.published_at = timezone.now()
     lineup.save(update_fields=["published_at"])
 
-    selected_member_ids = set(LineupSlot.objects.filter(unit__lineup=lineup, member__isnull=False).values_list("member_id", flat=True))
+    selected_member_ids = set(LineupSelection.objects.filter(lineup=lineup).values_list("member_id", flat=True))
 
     Attendance.objects.filter(event=lineup.event, member_id__in=selected_member_ids).update(status=Attendance.AttendanceStatus.SELECTED)
     Attendance.objects.filter(event=lineup.event).exclude(member_id__in=selected_member_ids).exclude(status__in=UNAVAILABLE_STATUSES).update(status=Attendance.AttendanceStatus.NOT_SELECTED)
@@ -60,6 +53,36 @@ def publish_lineup(lineup):
     return lineup
 
 
+def selected_members_by_position(lineup):
+    """Every LineupSelection for ``lineup``, grouped by the member's roster
+    position for the lineup's own team/season ("category") -- the read side
+    behind the published, member-facing Line-up card (mobile/views.py's
+    EventDetailView). A selected member with no TeamMembership on this team/
+    season (a guest call-up) lands in a catch-all "No position set" bucket
+    rather than being dropped -- mirrors CoachLineupView's own grouping."""
+    season = event_season(lineup.event)
+    member_ids = list(LineupSelection.objects.filter(lineup=lineup).values_list("member_id", flat=True))
+    memberships_by_member = {}
+    if season is not None:
+        memberships_by_member = {tm.member_id: tm for tm in TeamMembership.objects.filter(team=lineup.team, season=season, member_id__in=member_ids).select_related("position")}
+    members_by_id = {member.pk: member for member in Member.objects.filter(pk__in=member_ids)}
+
+    buckets = {}
+    for member_id in member_ids:
+        member = members_by_id.get(member_id)
+        if member is None:
+            continue
+        position = memberships_by_member[member_id].position if member_id in memberships_by_member else None
+        key = position.pk if position else None
+        bucket = buckets.setdefault(key, {"label": position.name if position else _("No position set"), "ordering": position.ordering if position else 9999, "members": []})
+        bucket["members"].append(member)
+
+    categories = sorted(buckets.values(), key=lambda bucket: (bucket["ordering"], bucket["label"]))
+    for bucket in categories:
+        bucket["members"].sort(key=lambda member: (member.last_name, member.first_name))
+    return categories
+
+
 def notify_dropout(event, member, note):
     """A player who was SELECTED in a published line-up reporting, after the
     fact, that they can no longer make it (mobile.views.EventDetailView.post's