Add invoice cancelled status, treasury event name, and voucher number backfill.

EOF

Co-authored-by: Cursor <cursoragent@cursor.com>

accounting/migrations/0008_invoice_cancelled_status.py

@@ -0,0 +1,25 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('accounting', '0007_backfill_voucher_numbers'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='invoice',
+            name='status',
+            field=models.CharField(
+                choices=[
+                    ('draft', 'Draft'),
+                    ('confirmed', 'Confirmed'),
+                    ('paid', 'Paid'),
+                    ('cancelled', 'Cancelled'),
+                ],
+                default='draft',
+                max_length=20,
+            ),
+        ),
+    ]