feat(comments): 支持编辑与管理可见历史，采纳展示改用楼层号

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/handler/moderation.go

@@ -187,6 +187,41 @@ func (h *Handlers) AdminPurgeComment(c *gin.Context) {
 	h.execContentAction(c, h.Moderation.PurgeComment)
 }
 
+// AdminCommentHistory 评论编辑历史（板域 scope；分页）
+func (h *Handlers) AdminCommentHistory(c *gin.Context) {
+	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil || id == 0 {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的 ID"})
+		return
+	}
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	size, _ := strconv.Atoi(c.DefaultQuery("size", "10"))
+	items, total, err := h.Comment.ListEditHistory(middleware.CurrentActor(c), uint(id), page, size)
+	if err != nil {
+		switch {
+		case errors.Is(err, service.ErrCommentNotFound):
+			c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+		case errors.Is(err, service.ErrCommentForbidden):
+			c.JSON(http.StatusForbidden, gin.H{"error": err.Error()})
+		default:
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "获取编辑历史失败"})
+		}
+		return
+	}
+	if page < 1 {
+		page = 1
+	}
+	if size < 1 || size > 50 {
+		size = 10
+	}
+	c.JSON(http.StatusOK, gin.H{
+		"items": items,
+		"total": total,
+		"page":  page,
+		"size":  size,
+	})
+}
+
 func (h *Handlers) execContentAction(c *gin.Context, fn func(*service.Actor, uint) error) {
 	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
 	if err != nil || id == 0 {