refactor: refactoring imports

将来ESMに移行しやすいように
Related: #7658

なんかmochaが起動しなくなってるけど理由不明
すぐ直したい

src/server/api/endpoints/admin/ad/create.ts

@@ -1,7 +1,7 @@
 import $ from 'cafy';
-import define from '../../../define';
-import { Ads } from '../../../../../models';
-import { genId } from '@/misc/gen-id';
+import define from '../../../define.js';
+import { Ads } from '@/models/index.js';
+import { genId } from '@/misc/gen-id.js';
 
 export const meta = {
 	tags: ['admin'],