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/service/notification_notify.go

@@ -0,0 +1,125 @@
+package service
+
+import (
+	"fmt"
+	"sort"
+
+	"metazone.cc/metalab/internal/model"
+)
+
+// checkAndNotifyAggregation 检查并生成点赞聚合通知
+func (s *NotificationService) checkAndNotifyAggregation(userID uint) {
+	summaries, err := s.repo.GetUnnotifiedDailyLikeSummaries(userID)
+	if err != nil || len(summaries) == 0 {
+		return
+	}
+
+	for _, sm := range summaries {
+		count := countUIDs(sm.LikerUIDs)
+		var content string
+		if count <= 3 {
+			content = fmt.Sprintf("你的文章被 %d 人点赞了", count)
+		} else {
+			content = fmt.Sprintf("你的文章被 %d 人点赞了", count)
+		}
+		_ = s.Create(userID, model.NotifyLikeAggregated,
+			"点赞汇总通知",
+			content,
+			nil, nil)
+		_ = s.repo.MarkDailyLikeSummaryNotified(sm.ID)
+	}
+}
+
+func countUIDs(uids string) int {
+	if uids == "" {
+		return 0
+	}
+	count := 1
+	for _, c := range uids {
+		if c == ',' {
+			count++
+		}
+	}
+	return count
+}
+
+// categoryTypes 分类→通知类型列表
+func categoryTypes(category string) []string {
+	switch category {
+	case "system":
+		return []string{model.NotifyAuditApproved, model.NotifyAuditRejected, model.NotifyPostApproved, model.NotifyPostRejected, model.NotifyLevelUp}
+	case "mention":
+		return []string{model.NotifyComment, model.NotifyCommentReply}
+	case "like":
+		return []string{model.NotifyLikeAggregated}
+	case "follow":
+		return []string{model.NotifyFollow}
+	default:
+		return []string{}
+	}
+}
+
+// sortNotifications 按 CreatedAt 降序排序
+func sortNotifications(items []model.Notification) {
+	sort.Slice(items, func(i, j int) bool {
+		return items[i].CreatedAt.After(items[j].CreatedAt)
+	})
+}
+
+// NotifyAuditApproved 审核通过通知
+func (s *NotificationService) NotifyAuditApproved(userID uint, auditType string, relatedID uint) {
+	typeName := model.AuditTypeNames[auditType]
+	if typeName == "" {
+		typeName = auditType
+	}
+	_ = s.Create(userID, model.NotifyAuditApproved,
+		"审核已通过",
+		"你的"+typeName+"修改已通过审核",
+		&relatedID, nil)
+}
+
+// NotifyAuditRejected 审核拒绝通知
+func (s *NotificationService) NotifyAuditRejected(userID uint, auditType, reason string, relatedID uint) {
+	typeName := model.AuditTypeNames[auditType]
+	if typeName == "" {
+		typeName = auditType
+	}
+	content := "你的" + typeName + "修改被拒绝"
+	if reason != "" {
+		content += "，理由：" + reason
+	}
+	_ = s.Create(userID, model.NotifyAuditRejected,
+		"审核未通过",
+		content,
+		&relatedID, nil)
+}
+
+// NotifyPostApproved 稿件审核通过通知
+func (s *NotificationService) NotifyPostApproved(userID uint, postTitle string, postID uint) {
+	title := "稿件审核通过"
+	content := "你的稿件《" + postTitle + "》已通过审核，现已公开发布"
+	_ = s.Create(userID, model.NotifyPostApproved, title, content, &postID, nil)
+}
+
+// NotifyPostRejected 稿件审核拒绝通知
+func (s *NotificationService) NotifyPostRejected(userID uint, postTitle, reason string, postID uint) {
+	title := "稿件审核未通过"
+	content := "你的稿件《" + postTitle + "》未通过审核"
+	if reason != "" {
+		content += "，理由：" + reason
+	}
+	_ = s.Create(userID, model.NotifyPostRejected, title, content, &postID, nil)
+}
+
+// NotifyFollow 关注通知（followerID 关注了 followeeID）
+func (s *NotificationService) NotifyFollow(followerID, followeeID uint) {
+	// 获取关注者用户名
+	followerName := s.getUsername(followerID)
+	if followerName == "" {
+		followerName = "一位用户"
+	}
+	title := "关注通知"
+	content := followerName + " 关注了你"
+	relID := followerID
+	_ = s.Create(followeeID, model.NotifyFollow, title, content, &relID, nil)
+}