feat: Studio 概览/分析补上阅读量 + 详情页 meta 行改版

- StudioOverview 新增 TotalViews 字段，GetOverviewByUserID 查询含 SUM(views_count)
- 新增 ViewTrendStore 接口和 AggregateViewsByAuthor，UNION ALL 合并已登录+访客阅读日志按日期聚合
- 数据分析页面新增阅读量趋势折线图（绿色，Chart.js）
- 概览和数据分析页面新增总阅读量统计卡片
- 详情页 meta 行改为标签格式：作者/阅读/点赞/收藏/评论/发布时间
- 移除详情页公开状态徽章，已锁定+理由仅作者可见

internal/service/repository.go

@@ -37,7 +37,7 @@ type postStore interface {
 	FindPageable(keyword string, offset, limit int) ([]model.Post, int64, error)
 	FindAdminPageable(keyword, status string, offset, limit int) ([]model.Post, int64, error)
 	FindByUserIDAndStatus(userID uint, status string, offset, limit int) ([]model.Post, int64, error)
-	GetOverviewByUserID(userID uint) (totalPosts, draftCount, pendingCount, approvedCount, rejectedCount int64, err error)
+	GetOverviewByUserID(userID uint) (totalPosts, draftCount, pendingCount, approvedCount, rejectedCount, totalViews int64, err error)
 	FindPendingRevisions(keyword string, offset, limit int) ([]model.Post, int64, error)
 	Update(post *model.Post) error
 	SoftDelete(id uint) error
@@ -231,3 +231,8 @@ type LikeTrendStore interface {
 type FavoriteTrendStore interface {
 	AggregateFavoritesByAuthor(userID uint, since string) ([]TrendPoint, error)
 }
+
+// ViewTrendStore 阅读量趋势聚合（ISP）
+type ViewTrendStore interface {
+	AggregateViewsByAuthor(userID uint, since string) ([]TrendPoint, error)
+}