feat: support subpath deployment with NEXT_PUBLIC_BASE_PATH environment variable

app/not-found.tsx

@@ -2,34 +2,43 @@
 
 import { useEffect } from "react";
 import { useAuthStore } from "@/stores/auth-store";
+import { getPathPrefix } from "@/lib/browser-navigation";
 
 export default function NotFound() {
   const isAuthenticated = useAuthStore((s) => s.isAuthenticated);
 
   useEffect(() => {
     if (!isAuthenticated) {
-      // Don't redirect admin routes to the webmail login page
-      const isAdminRoute = window.location.pathname === '/admin' || window.location.pathname.startsWith('/admin/');
+      const prefix = getPathPrefix();
+      // Don't redirect admin routes to the webmail login page. Admin paths
+      // are mounted relative to the deployment prefix, so account for it.
+      const adminBase = `${prefix}/admin`;
+      const isAdminRoute = window.location.pathname === adminBase || window.location.pathname.startsWith(`${adminBase}/`);
       if (!isAdminRoute) {
-        window.location.href = "/login";
+        window.location.href = `${prefix}/login`;
       }
     }
   }, [isAuthenticated]);
 
   if (!isAuthenticated) {
-    // Allow admin routes to render the 404 without redirecting
-    const isAdmin = typeof window !== 'undefined' &&
-      (window.location.pathname === '/admin' || window.location.pathname.startsWith('/admin/'));
+    let isAdmin = false;
+    if (typeof window !== 'undefined') {
+      const prefix = getPathPrefix();
+      const adminBase = `${prefix}/admin`;
+      isAdmin = window.location.pathname === adminBase || window.location.pathname.startsWith(`${adminBase}/`);
+    }
     if (!isAdmin) return null;
   }
 
+  const prefix = typeof window !== 'undefined' ? getPathPrefix() : '';
+
   return (
     <div className="min-h-screen flex items-center justify-center bg-background">
       <div className="text-center max-w-md px-4">
         <h1 className="text-4xl font-bold text-foreground mb-2">404</h1>
         <p className="text-muted-foreground mb-6">This page could not be found.</p>
         <a
-          href="/"
+          href={`${prefix}/`}
           className="inline-flex items-center px-4 py-2 bg-primary text-primary-foreground rounded-lg hover:opacity-90 transition-opacity"
         >
           Go home