feat(web): polish zone list and settings layout

Show Zone list as a table, align detail back navigation with proxy
route detail, and move edit/delete actions into the settings tab.

frontend/app/(main)/websites/[zoneId]/page-client.tsx

@@ -1,6 +1,5 @@
 'use client';
 
-import Link from 'next/link';
 import {usePathname, useRouter, useSearchParams} from 'next/navigation';
 import {useCallback, useMemo, useState} from 'react';
 import {useMutation, useQuery, useQueryClient} from '@tanstack/react-query';
@@ -118,11 +117,14 @@ export function ZonePageClient({zoneId}: {zoneId: number}) {
   if (overviewQuery.isError || !overviewQuery.data) {
     return (
       <div className="space-y-4 py-6 px-1">
-        <Button variant="ghost" size="sm" className="h-8 px-2" asChild>
-          <Link href="/websites">
-            <ArrowLeft className="mr-1 size-4" />
-            返回网站列表
-          </Link>
+        <Button
+          variant="ghost"
+          size="sm"
+          className="h-8 gap-1.5 px-0 text-xs"
+          onClick={() => router.back()}
+        >
+          <ArrowLeft className="size-3.5" />
+          返回
         </Button>
         <EmptyStateWithBorder
           icon={Globe}
@@ -141,7 +143,17 @@ export function ZonePageClient({zoneId}: {zoneId: number}) {
 
   return (
     <div className="space-y-6 py-6 px-1">
-      <div className="flex flex-col gap-4 sm:flex-row sm:items-center sm:justify-between">
+      <div className="space-y-4">
+        <Button
+          variant="ghost"
+          size="sm"
+          className="h-8 gap-1.5 px-0 text-xs"
+          onClick={() => router.back()}
+        >
+          <ArrowLeft className="size-3.5" />
+          返回
+        </Button>
+
         <div className="flex items-center gap-2">
           <Globe className="size-5 text-primary" />
           <div>
@@ -149,32 +161,6 @@ export function ZonePageClient({zoneId}: {zoneId: number}) {
             <p className="text-sm text-muted-foreground">Zone 网站管理</p>
           </div>
         </div>
-        <div className="flex flex-wrap gap-2">
-          <Button variant="outline" size="sm" className="h-7 text-xs" asChild>
-            <Link href="/websites">
-              <ArrowLeft className="mr-1 size-3.5" />
-              返回
-            </Link>
-          </Button>
-          <Button
-            variant="outline"
-            size="sm"
-            className="h-7 text-xs"
-            onClick={() => setEditZone(true)}
-          >
-            <Pencil className="mr-1 size-3.5" />
-            编辑 Zone
-          </Button>
-          <Button
-            variant="destructive"
-            size="sm"
-            className="h-7 text-xs"
-            onClick={() => setConfirmDelete(true)}
-          >
-            <Trash2 className="mr-1 size-3.5" />
-            删除 Zone
-          </Button>
-        </div>
       </div>
 
       <Tabs value={activeTab} onValueChange={setActiveTab} className="w-full">
@@ -211,20 +197,48 @@ export function ZonePageClient({zoneId}: {zoneId: number}) {
           <ZoneCertificatesPanel domains={overview.domains} certificates={certificates} />
         </TabsContent>
         <TabsContent value="settings">
-          <div className="rounded-lg border p-4">
-            <p className="text-sm font-semibold">Zone 设置</p>
-            <p className="mt-1 text-sm text-muted-foreground">
-              根域和备注可在此 Zone 的编辑操作中维护。
-            </p>
-            <Button
-              variant="outline"
-              size="sm"
-              className="mt-4 h-7 text-xs"
-              onClick={() => setEditZone(true)}
-            >
-              <Pencil className="mr-1 size-3.5" />
-              编辑根域与备注
-            </Button>
+          <div className="space-y-4">
+            <div className="rounded-lg border p-4">
+              <p className="text-sm font-semibold">基本信息</p>
+              <p className="mt-1 text-sm text-muted-foreground">
+                维护 Zone 的可注册根域。根域变更后，请确认其下域名仍归属该根域。
+              </p>
+              <div className="mt-3 grid gap-2 text-sm sm:grid-cols-2">
+                <div>
+                  <p className="text-xs text-muted-foreground">当前根域</p>
+                  <p className="mt-1 font-mono text-[13px] font-medium">{overview.zone.domain}</p>
+                </div>
+                <div>
+                  <p className="text-xs text-muted-foreground">域名数量</p>
+                  <p className="mt-1 font-mono text-[13px] font-medium">{overview.domains.length}</p>
+                </div>
+              </div>
+              <Button
+                variant="outline"
+                size="sm"
+                className="mt-4 h-7 text-xs"
+                onClick={() => setEditZone(true)}
+              >
+                <Pencil className="mr-1 size-3.5" />
+                编辑根域
+              </Button>
+            </div>
+
+            <div className="rounded-lg border border-destructive/30 p-4">
+              <p className="text-sm font-semibold text-destructive">危险操作</p>
+              <p className="mt-1 text-sm text-muted-foreground">
+                删除 Zone 前须清空其下全部域名；删除后不可恢复。
+              </p>
+              <Button
+                variant="destructive"
+                size="sm"
+                className="mt-4 h-7 text-xs"
+                onClick={() => setConfirmDelete(true)}
+              >
+                <Trash2 className="mr-1 size-3.5" />
+                删除 Zone
+              </Button>
+            </div>
           </div>
         </TabsContent>
       </Tabs>