feat: Add specific shift date field for multi-day events with date selector in EventEditor and date badge in ShiftMatrix

backend/apps/events/migrations/0004_shift_date.py

@@ -0,0 +1,18 @@
+# Generated by Django 6.0.7 on 2026-07-31 08:51
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0003_event_is_active'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='shift',
+            name='date',
+            field=models.DateField(blank=True, help_text='Spezifisches Datum für mehrtägige Veranstaltungen', null=True),
+        ),
+    ]