feat: support subpath deployment with NEXT_PUBLIC_BASE_PATH environment variable

app/[locale]/login/page.tsx

@@ -411,7 +411,8 @@ export default function LoginPage() {
     const verifier = generateCodeVerifier();
     const challenge = await generateCodeChallenge(verifier);
     const state = generateState();
-    const redirectUri = `${window.location.origin}/${params.locale}/auth/callback`;
+    const prefix = getPathPrefix(params.locale as string);
+    const redirectUri = `${window.location.origin}${prefix}/${params.locale}/auth/callback`;
 
     sessionStorage.setItem("oauth_code_verifier", verifier);
     sessionStorage.setItem("oauth_state", state);

app/manifest.ts

@@ -2,6 +2,12 @@ import type { MetadataRoute } from "next";
 
 export const dynamic = "force-dynamic";
 
+// Manifest paths must include the deployment subpath - browsers resolve them
+// against the document origin, not the manifest's location, and Next.js does
+// not auto-prefix string literals inside MetadataRoute payloads.
+const BASE_PATH = (process.env.NEXT_PUBLIC_BASE_PATH ?? "").replace(/\/+$/, "");
+const withBase = (p: string) => `${BASE_PATH}${p}`;
+
 export default function manifest(): MetadataRoute.Manifest {
   const appName =
     process.env.APP_NAME ||
@@ -21,26 +27,26 @@ export default function manifest(): MetadataRoute.Manifest {
 
   const icons: MetadataRoute.Manifest["icons"] = hasCustomIcon
     ? [
-        { src: "/api/pwa-icon/192", sizes: "192x192", type: "image/png", purpose: "any" },
-        { src: "/api/pwa-icon/512", sizes: "512x512", type: "image/png", purpose: "any" },
-        { src: "/api/pwa-icon/192", sizes: "192x192", type: "image/png", purpose: "maskable" },
-        { src: "/api/pwa-icon/512", sizes: "512x512", type: "image/png", purpose: "maskable" },
+        { src: withBase("/api/pwa-icon/192"), sizes: "192x192", type: "image/png", purpose: "any" },
+        { src: withBase("/api/pwa-icon/512"), sizes: "512x512", type: "image/png", purpose: "any" },
+        { src: withBase("/api/pwa-icon/192"), sizes: "192x192", type: "image/png", purpose: "maskable" },
+        { src: withBase("/api/pwa-icon/512"), sizes: "512x512", type: "image/png", purpose: "maskable" },
       ]
     : [
-        { src: "/icon-192x192.png", sizes: "192x192", type: "image/png", purpose: "any" },
-        { src: "/icon-512x512.png", sizes: "512x512", type: "image/png", purpose: "any" },
-        { src: "/icon-maskable-light-192x192.png", sizes: "192x192", type: "image/png", purpose: "maskable" },
-        { src: "/icon-maskable-light-512x512.png", sizes: "512x512", type: "image/png", purpose: "maskable" },
-        { src: "/icon-maskable-dark-192x192.png", sizes: "192x192", type: "image/png", purpose: "maskable" },
-        { src: "/icon-maskable-dark-512x512.png", sizes: "512x512", type: "image/png", purpose: "maskable" },
+        { src: withBase("/icon-192x192.png"), sizes: "192x192", type: "image/png", purpose: "any" },
+        { src: withBase("/icon-512x512.png"), sizes: "512x512", type: "image/png", purpose: "any" },
+        { src: withBase("/icon-maskable-light-192x192.png"), sizes: "192x192", type: "image/png", purpose: "maskable" },
+        { src: withBase("/icon-maskable-light-512x512.png"), sizes: "512x512", type: "image/png", purpose: "maskable" },
+        { src: withBase("/icon-maskable-dark-192x192.png"), sizes: "192x192", type: "image/png", purpose: "maskable" },
+        { src: withBase("/icon-maskable-dark-512x512.png"), sizes: "512x512", type: "image/png", purpose: "maskable" },
       ];
 
   return {
     name: appName,
     short_name: shortName,
     description,
-    start_url: "/",
-    scope: "/",
+    start_url: withBase("/"),
+    scope: withBase("/"),
     display: "standalone",
     orientation: "portrait-primary",
     theme_color: themeColor,
@@ -48,8 +54,8 @@ export default function manifest(): MetadataRoute.Manifest {
     icons,
     categories: ["productivity"],
     screenshots: [
-      { src: "/screenshot-540x720.png", sizes: "540x720", type: "image/png" },
-      { src: "/screenshot-1280x720.png", sizes: "1280x720", type: "image/png" },
+      { src: withBase("/screenshot-540x720.png"), sizes: "540x720", type: "image/png" },
+      { src: withBase("/screenshot-1280x720.png"), sizes: "1280x720", type: "image/png" },
     ],
   };
 }

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