Replace websocket flow with SSE support in backend.

Update handlers, services, router, and data conversion logic to support server-sent events and related message pipeline changes.

Made-with: Cursor

internal/dto/converter.go

@@ -284,6 +284,7 @@ func ConvertPostToResponse(post *model.Post, isLiked, isFavorited bool) *PostRes
 		Title:          post.Title,
 		Content:        post.Content,
 		Images:         images,
+		Status:         string(post.Status),
 		LikesCount:     post.LikesCount,
 		CommentsCount:  post.CommentsCount,
 		FavoritesCount: post.FavoritesCount,
@@ -293,6 +294,7 @@ func ConvertPostToResponse(post *model.Post, isLiked, isFavorited bool) *PostRes
 		IsLocked:       post.IsLocked,
 		IsVote:         post.IsVote,
 		CreatedAt:      FormatTime(post.CreatedAt),
+		UpdatedAt:      FormatTime(post.UpdatedAt),
 		Author:         author,
 		IsLiked:        isLiked,
 		IsFavorited:    isFavorited,