refactor: 文件行数超标拆解（7个文件→14个文件，全部≤200行）

- 移动本地接口定义到 interfaces.go 和 admin/interfaces.go
- favorite_controller.go → favorite_item_controller.go
- space_controller.go → space_loaders.go
- settings_controller.go → settings_api_audit.go
- admin_energy_controller.go → admin_energy_api_controller.go
- admin_post_controller.go → admin_post_action_controller.go
- comment_repo.go → comment_mention_repo.go
- post_repo.go → post_stats_repo.go

internal/controller/favorite_item_controller.go

@@ -0,0 +1,143 @@
+package controller
+
+import (
+	"net/http"
+	"strconv"
+
+	"metazone.cc/metalab/internal/common"
+
+	"github.com/gin-gonic/gin"
+)
+
+// ListFolderItems 获取收藏夹内文章列表 GET /api/folders/:id/posts
+func (fc *FavoriteController) ListFolderItems(c *gin.Context) {
+	uid, _, _ := common.GetGinUser(c) // 允许未登录查看公开收藏夹
+
+	folderID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的收藏夹 ID")
+		return
+	}
+
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
+
+	result, err := fc.svc.ListFolderItems(uid, uint(folderID), page, pageSize)
+	if err != nil {
+		if err == common.ErrPermissionDenied {
+			common.Error(c, http.StatusForbidden, "该收藏夹未公开")
+			return
+		}
+		common.Error(c, http.StatusInternalServerError, "获取失败")
+		return
+	}
+
+	common.Ok(c, result)
+}
+
+// AddToFolder 收藏文章 POST /api/folders/:id/posts
+func (fc *FavoriteController) AddToFolder(c *gin.Context) {
+	uid, _, ok := common.GetGinUser(c)
+	if !ok {
+		common.Error(c, http.StatusUnauthorized, "请先登录")
+		return
+	}
+
+	folderID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的收藏夹 ID")
+		return
+	}
+
+	var req struct {
+		PostID uint `json:"post_id"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil || req.PostID == 0 {
+		common.Error(c, http.StatusBadRequest, "参数错误")
+		return
+	}
+
+	if err := fc.svc.AddFavorite(uid, req.PostID, func() *uint { v := uint(folderID); return &v }()); err != nil {
+		common.Error(c, http.StatusBadRequest, err.Error())
+		return
+	}
+
+	common.OkMessage(c, "收藏成功")
+}
+
+// RemoveFromFolder 取消收藏 DELETE /api/folders/:id/posts/:postId
+func (fc *FavoriteController) RemoveFromFolder(c *gin.Context) {
+	uid, _, ok := common.GetGinUser(c)
+	if !ok {
+		common.Error(c, http.StatusUnauthorized, "请先登录")
+		return
+	}
+
+	folderID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的收藏夹 ID")
+		return
+	}
+
+	postID, err := strconv.ParseUint(c.Param("postId"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的文章 ID")
+		return
+	}
+
+	if err := fc.svc.RemoveFavorite(uid, uint(postID)); err != nil {
+		common.Error(c, http.StatusBadRequest, err.Error())
+		return
+	}
+
+	_ = folderID // 移除不依赖具体收藏夹
+	common.OkMessage(c, "已取消收藏")
+}
+
+// GetPostStatus 查询文章收藏状态 GET /api/posts/:id/folder-status
+func (fc *FavoriteController) GetPostStatus(c *gin.Context) {
+	uid, _, ok := common.GetGinUser(c)
+	if !ok {
+		common.Ok(c, gin.H{"favorited": false})
+		return
+	}
+
+	postID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的文章 ID")
+		return
+	}
+
+	status, err := fc.svc.GetPostFavoriteStatus(uid, uint(postID))
+	if err != nil {
+		common.Error(c, http.StatusInternalServerError, "查询失败")
+		return
+	}
+
+	common.Ok(c, status)
+}
+
+// ToggleFavorite 切换收藏 POST /api/posts/:id/favorite
+func (fc *FavoriteController) ToggleFavorite(c *gin.Context) {
+	uid, _, ok := common.GetGinUser(c)
+	if !ok {
+		common.Error(c, http.StatusUnauthorized, "请先登录")
+		return
+	}
+
+	postID, err := strconv.ParseUint(c.Param("id"), 10, 64)
+	if err != nil {
+		common.Error(c, http.StatusBadRequest, "无效的文章 ID")
+		return
+	}
+
+	isFavored, err := fc.svc.ToggleFavorite(uid, uint(postID))
+	if err != nil {
+		common.Error(c, http.StatusInternalServerError, "操作失败")
+		return
+	}
+
+	common.Ok(c, gin.H{
+		"favorited": isFavored,
+	})
+}