list sharing implemented w. passing UTs & FTs; changes to apps.dashboard.urls, .models, .views & .tests.test_views to accomodate; functional_tests.test_sharing also ensures sharing visible in UX; templates/apps/dashboard/list.html & /my_lists.html updated with django templating & for loops

src/apps/dashboard/migrations/0003_list_shared_with.py

@@ -0,0 +1,20 @@
+# Generated by Django 6.0 on 2026-02-18 18:13
+
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('dashboard', '0002_list_owner'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='list',
+            name='shared_with',
+            field=models.ManyToManyField(blank=True, related_name='shared_lists', to=settings.AUTH_USER_MODEL),
+        ),
+    ]