Season-scope claim history, self-service second-child claims, redesign approval screen

Signed-in parents get their details locked and pre-filled on the claim
form instead of retyped; approving links to their existing user and
merges into their existing family instead of creating a duplicate.
The approval screen is now a card grid with a searchable, pre-selected
child dropdown and a reason modal for rejection. The "already dealt
with" history is scoped to the current season.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

members/migrations/0006_parentclaim_submitted_by_user.py

@@ -0,0 +1,21 @@
+# Generated by Django 6.0.6 on 2026-08-11 21:39
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('members', '0005_parent_claim'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='parentclaim',
+            name='submitted_by_user',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='submitted_parent_claims', to=settings.AUTH_USER_MODEL, verbose_name='submitted by'),
+        ),
+    ]