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/migrations/0025_remove_lineupunit_lineup_lineupselection_and_more.py

@@ -0,0 +1,44 @@
+# Generated by Django 6.0.6 on 2026-08-22 14:23
+
+import django.db.models.deletion
+import uuid
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0024_lineup_lineupunit_lineupslot'),
+        ('members', '0006_parentclaim_submitted_by_user'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='lineupunit',
+            name='lineup',
+        ),
+        migrations.CreateModel(
+            name='LineupSelection',
+            fields=[
+                ('created', models.DateTimeField(auto_now_add=True, verbose_name='created')),
+                ('modified', models.DateTimeField(auto_now=True, verbose_name='modified')),
+                ('id', models.UUIDField(default=uuid.uuid4, editable=False, primary_key=True, serialize=False)),
+                ('lineup', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='selections', to='events.lineup', verbose_name='line-up')),
+                ('member', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='lineup_selections', to='members.member', verbose_name='member')),
+            ],
+            options={
+                'verbose_name': 'line-up selection',
+                'verbose_name_plural': 'line-up selections',
+            },
+        ),
+        migrations.DeleteModel(
+            name='LineupSlot',
+        ),
+        migrations.DeleteModel(
+            name='LineupUnit',
+        ),
+        migrations.AddConstraint(
+            model_name='lineupselection',
+            constraint=models.UniqueConstraint(fields=('lineup', 'member'), name='unique_selection_per_lineup_per_member'),
+        ),
+    ]