style: enhance visibility of Tenant view mode toggle buttons

- Add primary background and text color to active TabsTrigger state
- Add border and darker background to TabsList container
- Increase font weight for better readability

adminfront/src/features/tenants/routes/TenantListPage.tsx

@@ -584,12 +584,18 @@ function TenantListPage() {
               onValueChange={(v) => setViewMode(v as "list" | "hierarchy")}
               className="w-[280px]"
             >
-              <TabsList className="grid w-full grid-cols-2">
-                <TabsTrigger value="list" className="text-xs">
+              <TabsList className="grid w-full grid-cols-2 p-1 bg-muted/60 border border-border/50">
+                <TabsTrigger
+                  value="list"
+                  className="text-xs font-semibold data-[state=active]:bg-primary data-[state=active]:text-primary-foreground transition-all"
+                >
                   <List className="w-3.5 h-3.5 mr-1.5" />
                   {t("ui.admin.tenants.view.list", "평면 목록")}
                 </TabsTrigger>
-                <TabsTrigger value="hierarchy" className="text-xs">
+                <TabsTrigger
+                  value="hierarchy"
+                  className="text-xs font-semibold data-[state=active]:bg-primary data-[state=active]:text-primary-foreground transition-all"
+                >
                   <Network className="w-3.5 h-3.5 mr-1.5" />
                   {t("ui.admin.tenants.view.hierarchy", "계층 구조")}
                 </TabsTrigger>