feat(admin): 独立后台壳、站点分析与聊天监管，公开站拆出主题切换与访问埋点

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

backend/handler/setting.go

@@ -34,6 +34,7 @@ type updateSettingsRequest struct {
 	AnimCodeFold         *bool   `json:"anim_code_fold"`
 	AnimSmoothScroll     *bool   `json:"anim_smooth_scroll"`
 	AnimChrome           *bool   `json:"anim_chrome"`
+	PostLinkNewTab       *bool   `json:"post_link_new_tab"`
 }
 
 func settingsPayload(saved service.PublicSiteSettings) gin.H {
@@ -51,6 +52,7 @@ func settingsPayload(saved service.PublicSiteSettings) gin.H {
 		"anim_code_fold":         saved.AnimCodeFold,
 		"anim_smooth_scroll":     saved.AnimSmoothScroll,
 		"anim_chrome":            saved.AnimChrome,
+		"post_link_new_tab":      saved.PostLinkNewTab,
 	}
 }
 
@@ -65,7 +67,7 @@ func (h *Handlers) UpdateSettings(c *gin.Context) {
 		req.SiteDescription == nil && req.AllowRegister == nil && req.AllowComments == nil &&
 		req.PostCooldownHours == nil && req.CodeBlockAutoFold == nil && req.CodeBlockFoldLines == nil &&
 		req.UIAnimations == nil && req.AnimCodeFold == nil && req.AnimSmoothScroll == nil &&
-		req.AnimChrome == nil {
+		req.AnimChrome == nil && req.PostLinkNewTab == nil {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "未提供任何可更新的设置项"})
 		return
 	}
@@ -168,6 +170,12 @@ func (h *Handlers) UpdateSettings(c *gin.Context) {
 			return
 		}
 	}
+	if req.PostLinkNewTab != nil {
+		if err := h.Setting.SetPostLinkNewTab(*req.PostLinkNewTab); err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "保存站点设置失败"})
+			return
+		}
+	}
 
 	saved, err := h.Setting.Public()
 	if err != nil {