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

EOF

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

accounting/migrations/0009_treasury_event_name.py

@@ -0,0 +1,30 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    """
+    DB already has event_name (NOT NULL) from an earlier manual/out-of-band change.
+    Sync Django state and ensure NULLs become empty string so inserts never omit the column.
+    """
+
+    dependencies = [
+        ('accounting', '0008_invoice_cancelled_status'),
+    ]
+
+    operations = [
+        migrations.SeparateDatabaseAndState(
+            state_operations=[
+                migrations.AddField(
+                    model_name='treasurytxn',
+                    name='event_name',
+                    field=models.CharField(blank=True, default='', max_length=200),
+                ),
+            ],
+            database_operations=[
+                migrations.RunSQL(
+                    sql="UPDATE accounting_treasury_txns SET event_name = '' WHERE event_name IS NULL;",
+                    reverse_sql=migrations.RunSQL.noop,
+                ),
+            ],
+        ),
+    ]