refactor: 文件行数超标拆解（Service + Controller 9/16 完成）

- Service 层：energy_service → energize/operations/admin/query 四文件
- Service 层：post_service → helpers/audit + 核心 CRUD 保留
- Service 层：favorite_service → items + 核心文件夹操作保留
- Service 层：auth_service → password + 核心注册/登录保留
- Service 层：notification_service → notify + 核心列表/已读保留
- Service 层：audit_service → review + 核心列表/详情保留
- Controller 层：studio_controller → page/write/api/post_api/action 五文件
- Controller 层：post_controller → page/api/upload 三文件
- Controller 层：comment_controller → list/write/action/upload 四文件
- 清理未使用导入（notification_service.go 移除 fmt）

internal/controller/comment_list_controller.go

@@ -0,0 +1,52 @@
+package controller
+
+import (
+	"net/http"
+	"strconv"
+
+	"metazone.cc/metalab/internal/common"
+
+	"github.com/gin-gonic/gin"
+)
+
+// ListRootComments 获取文章顶级评论 GET /api/posts/:id/comments
+func (ctrl *CommentController) ListRootComments(c *gin.Context) {
+	postID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的文章ID")
+		return
+	}
+
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
+
+	comments, total, err := ctrl.commentService.ListRootComments(uint(postID), page, pageSize)
+	if err != nil {
+		common.Error(c, http.StatusInternalServerError, "获取评论失败")
+		return
+	}
+
+	common.Ok(c, gin.H{
+		"items":       comments,
+		"total":       total,
+		"page":        page,
+		"total_pages": common.PageCount(total, pageSize),
+	})
+}
+
+// ListReplies 获取顶级评论的全部回复 GET /api/posts/:id/comments/:root_id/replies
+func (ctrl *CommentController) ListReplies(c *gin.Context) {
+	rootID, err := strconv.ParseUint(c.Param("root_id"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的评论ID")
+		return
+	}
+
+	replies, err := ctrl.commentService.ListReplies(uint(rootID))
+	if err != nil {
+		common.Error(c, http.StatusInternalServerError, "获取回复失败")
+		return
+	}
+
+	common.Ok(c, gin.H{"replies": replies})
+}