fix: enable data migration

db/migrations/20231229091800_add_service_fee.up.sql

@@ -1,7 +1,7 @@
+alter table invoices ALTER COLUMN fee SET DEFAULT 0;
 alter table invoices ADD COLUMN IF NOT EXISTS service_fee bigint default 0;
 alter table invoices ADD COLUMN IF NOT EXISTS routing_fee bigint default 0;
 
--- maybe manually migrate existing data?
--- alter table invoices ALTER COLUMN fee SET DEFAULT 0;
--- update invoices set fee = 0 where fee IS NULL;
--- update invoices set routing_fee = fee where routing_fee=0;
+-- migrate existing data
+update invoices set fee = 0 where fee IS NULL;
+update invoices set routing_fee = fee where fee > 0;