feat: add WebSocket notifications for new comments

- Introduced enriched comment retrieval with user information and like statistics.
- Implemented WebSocket notifications to notify users of new comments on content.
- Updated dependency injection to include `EventsGateway` and `RealtimeModule`.

backend/src/comments/repositories/comments.repository.ts

@@ -45,6 +45,27 @@ export class CommentsRepository {
 		return results[0];
 	}
 
+	async findOneEnriched(id: string) {
+		const results = await this.databaseService.db
+			.select({
+				id: comments.id,
+				text: comments.text,
+				parentId: comments.parentId,
+				createdAt: comments.createdAt,
+				updatedAt: comments.updatedAt,
+				user: {
+					uuid: users.uuid,
+					username: users.username,
+					displayName: users.displayName,
+					avatarUrl: users.avatarUrl,
+				},
+			})
+			.from(comments)
+			.innerJoin(users, eq(comments.userId, users.uuid))
+			.where(and(eq(comments.id, id), isNull(comments.deletedAt)));
+		return results[0];
+	}
+
 	async delete(id: string) {
 		await this.databaseService.db
 			.update(comments)