merge: catch up with feature/helcim-plan-consolidation base

# Conflicts:
#	server/api/auth/member.get.js
#	server/api/members/update-contribution.post.js
#	tests/server/api/update-contribution.test.js

server/api/members/cancel-subscription.post.js

@@ -34,6 +34,7 @@ export default defineEventHandler(async (event) => {
           paymentMethod: 'none',
           subscriptionEndDate: new Date(),
         },
+        $unset: { nextBillingDate: 1 },
       },
       { runValidators: false }
     );