core: build with plugins

packages/hydrooj/src/plugin-api.ts

@@ -53,3 +53,6 @@ export * from '@hydrooj/framework/validator';
 export * as StorageService from './service/storage';
 export { EventMap } from './service/bus';
 export { db, pwsh };
+
+// to load ctx.scoreboard
+export { } from './handler/contest';