debug: 添加站点设置持久化调试日志，追踪 Set/Get 链路

internal/controller/admin/site_setting_controller.go

@@ -1,6 +1,7 @@
 package admin
 
 import (
+	"log"
 	"net/http"
 	"strconv"
 
@@ -87,6 +88,10 @@ func (sc *SiteSettingController) ThemePage(c *gin.Context) {
 func (sc *SiteSettingController) GetSettings(c *gin.Context) {
 	all := sc.settingService.GetSettings()
 	audit := sc.settingService.GetAuditSettings(sc.defaults)
+	log.Printf("[GetSettings] all=%d keys audit=%+v", len(all), audit)
+	if v, ok := all["registration.enabled"]; ok {
+		log.Printf("[GetSettings] registration.enabled=%q", v)
+	}
 	common.Ok(c, gin.H{
 		"all":   all,
 		"audit": audit,