feat: add ContentsModule to CommentsModule with forward reference

- Updated imports in `comments.module.ts` to include `ContentsModule` using `forwardRef` for dependency resolution.

backend/src/comments/comments.module.ts

@@ -1,5 +1,6 @@
-import { Module } from "@nestjs/common";
+import { Module, forwardRef } from "@nestjs/common";
 import { AuthModule } from "../auth/auth.module";
+import { ContentsModule } from "../contents/contents.module";
 import { RealtimeModule } from "../realtime/realtime.module";
 import { S3Module } from "../s3/s3.module";
 import { CommentsController } from "./comments.controller";
@@ -8,7 +9,12 @@ import { CommentLikesRepository } from "./repositories/comment-likes.repository"
 import { CommentsRepository } from "./repositories/comments.repository";
 
 @Module({
-	imports: [AuthModule, S3Module, RealtimeModule],
+	imports: [
+		AuthModule,
+		S3Module,
+		RealtimeModule,
+		forwardRef(() => ContentsModule),
+	],
 	controllers: [CommentsController],
 	providers: [CommentsService, CommentsRepository, CommentLikesRepository],
 	exports: [CommentsService],