refactor(zone): remove legacy route domain storage

第二阶段清理：删除 of_managed_domains 与 of_proxy_routes 冗余域名/证书列，
移除 ManagedDomain 模型与 API、路由侧 legacy 字段维护，以及前端 WebsiteService。
ImportLegacy 在旧列/旧表缺失时跳过对应源，保持幂等。

frontend/lib/services/index.ts

@@ -41,7 +41,6 @@ import {
   TlsCertificateService,
   UptimeKumaService,
   WafService,
-  WebsiteService,
   ZoneDomainService,
   ZoneService,
 } from './openflare';
@@ -68,7 +67,6 @@ const services = {
   openflareApplyLog: ApplyLogService,
   openflareDashboard: DashboardService,
   openflareWaf: WafService,
-  openflareWebsite: WebsiteService,
   openflareZone: ZoneService,
   openflareZoneDomain: ZoneDomainService,
   openflareTls: TlsCertificateService,
@@ -191,7 +189,6 @@ export {
   ApplyLogService,
   DashboardService,
   WafService,
-  WebsiteService,
   TlsCertificateService,
   DnsAccountService,
   PagesService,
@@ -216,7 +213,6 @@ export type {
   WAFIPGroup,
   WAFRuleGroup,
   WAFSiteRuleGroups,
-  ManagedDomainItem,
   TlsCertificateItem,
   DnsAccountItem,
   PagesProject,