fix: resolve all build-test and code-check failures

- Fix Go backend mnd (magic number) and revive lint issues in zone stats.
- Remove unused React/Lucide imports and variables in zone overview.
- Add generateStaticParams and Suspense wrapper for websites/[zoneId] page to support Next.js static HTML export.
- Remove next/font/google dependency to allow fully offline frontend compilation.
- Fix hardcoded time dependency in ssl_renew_test.go.
- Fix async_tasks_test.go to respect minimum 90-day retention clamping in database auto-cleanup.
- Add Zone and ZoneDomain models to test database AutoMigrate schemas.
- Update integration tests to use the new zone_domain_ids route binding scheme.

frontend/app/layout.tsx

@@ -1,5 +1,4 @@
 import type {Metadata} from "next";
-import {Inter} from "next/font/google";
 import {Toaster} from "@/components/ui/sonner";
 import {ThemeProvider} from "@/components/layout/theme-provider";
 import {CustomThemeProvider} from "@/lib/theme";
@@ -11,12 +10,6 @@ import {SiteTitleUpdater} from "@/components/providers/title-updater";
 import {RobotsMeta} from "@/components/layout/robots-meta";
 import "./globals.css";
 
-const inter = Inter({
-  subsets: ["latin"],
-  variable: "--font-inter",
-  display: "swap",
-});
-
 export const metadata: Metadata = {
   title: "OpenFlare",
   description: "OpenFlare 边缘节点与反向代理管理平台",
@@ -30,7 +23,7 @@ export default function RootLayout({
   return (
     <html
       lang="zh-CN"
-      className={`hide-scrollbar font-sans ${inter.variable}`}
+      className="hide-scrollbar font-sans"
       suppressHydrationWarning
     >
       <body