fix: skip intl middleware for paths already containing a locale prefix

i18n/routing.ts

@@ -1,9 +1,21 @@
 import { defineRouting } from 'next-intl/routing';
 
+// Locale prefix mode can be configured via NEXT_PUBLIC_LOCALE_PREFIX.
+// - "never"    (default): /settings — locale from cookie/Accept-Language
+// - "always":             /en/settings — locale always in the URL
+// - "as-needed":          /settings for default locale, /fr/settings otherwise
+// When proxying Bulwark under a sub-path (NEXT_PUBLIC_BASE_PATH), "always" is
+// recommended to avoid next-intl rewrite loops caused by locale detection
+// conflicting with the proxy's path rewriting.
+const localePrefix = (process.env.NEXT_PUBLIC_LOCALE_PREFIX ?? 'never') as
+  | 'never'
+  | 'always'
+  | 'as-needed';
+
 export const routing = defineRouting({
   locales: ['en', 'fr', 'de', 'es', 'it', 'ja', 'ko', 'lv', 'nl', 'pl', 'pt', 'ru', 'zh'],
   defaultLocale: 'en',
-  localePrefix: 'never'
+  localePrefix
 });
 
 export const locales = routing.locales;

proxy.ts

@@ -34,8 +34,16 @@ export function proxy(request: NextRequest) {
   const pathname = request.nextUrl.pathname;
   const isAdminRoute = pathname === '/admin' || pathname.startsWith('/admin/');
 
+  // When localePrefix is 'always', paths that already have a locale prefix
+  // (e.g. /en/settings) should not be re-processed by the intl middleware —
+  // doing so can trigger rewrite loops when combined with a proxy basePath.
+  const locales = routing.locales as readonly string[];
+  const hasLocalePrefix = locales.some(
+    (l) => pathname === `/${l}` || pathname.startsWith(`/${l}/`)
+  );
+
   let intlResponse: ReturnType<typeof intlMiddleware> | null = null;
-  if (!isAdminRoute) {
+  if (!isAdminRoute && !hasLocalePrefix) {
     try {
       intlResponse = intlMiddleware(request);
     } catch (error) {