feat: add comments functionality and integrate Socket.io for real-time updates

- Implemented a full comments module in the backend with repository, service, controller, and DTOs using NestJS.
- Added frontend support for comments with a `CommentSection` component and integration into content pages.
- Introduced `SocketProvider` on the frontend and integrated Socket.io for real-time communication.
- Updated dependencies and configurations for Socket.io and WebSockets support.

backend/src/comments/comments.controller.ts

@@ -0,0 +1,41 @@
+import {
+	Body,
+	Controller,
+	Delete,
+	Get,
+	Param,
+	Post,
+	Req,
+	UseGuards,
+} from "@nestjs/common";
+import { AuthGuard } from "../auth/guards/auth.guard";
+import type { AuthenticatedRequest } from "../common/interfaces/request.interface";
+import { CommentsService } from "./comments.service";
+import { CreateCommentDto } from "./dto/create-comment.dto";
+
+@Controller()
+export class CommentsController {
+	constructor(private readonly commentsService: CommentsService) {}
+
+	@Get("contents/:contentId/comments")
+	findAllByContentId(@Param("contentId") contentId: string) {
+		return this.commentsService.findAllByContentId(contentId);
+	}
+
+	@Post("contents/:contentId/comments")
+	@UseGuards(AuthGuard)
+	create(
+		@Req() req: AuthenticatedRequest,
+		@Param("contentId") contentId: string,
+		@Body() dto: CreateCommentDto,
+	) {
+		return this.commentsService.create(req.user.sub, contentId, dto);
+	}
+
+	@Delete("comments/:id")
+	@UseGuards(AuthGuard)
+	remove(@Req() req: AuthenticatedRequest, @Param("id") id: string) {
+		const isAdmin = req.user.role === "admin" || req.user.role === "moderator";
+		return this.commentsService.remove(req.user.sub, id, isAdmin);
+	}
+}