diff --git a/apps/admin/src/app/dashboard/companies/[id]/page.tsx b/apps/admin/src/app/dashboard/companies/[id]/page.tsx
index e3481f9..f766f3a 100644
--- a/apps/admin/src/app/dashboard/companies/[id]/page.tsx
+++ b/apps/admin/src/app/dashboard/companies/[id]/page.tsx
@@ -284,7 +284,7 @@ function createFormState(company: CompanyDetail): FormState {
       publicCountry: company.brand?.publicCountry ?? '',
       websiteUrl: company.brand?.websiteUrl ?? '',
       whatsappNumber: company.brand?.whatsappNumber ?? '',
-      defaultLocale: company.brand?.defaultLocale ?? 'en',
+      defaultLocale: company.brand?.defaultLocale ?? 'ar',
       defaultCurrency: company.brand?.defaultCurrency ?? 'MAD',
       isListedOnCarplace: company.brand?.isListedOnCarplace ?? true,
     },
diff --git a/apps/admin/src/app/layout.tsx b/apps/admin/src/app/layout.tsx
index f9dbafe..a6d9564 100644
--- a/apps/admin/src/app/layout.tsx
+++ b/apps/admin/src/app/layout.tsx
@@ -1,4 +1,5 @@
 import type { Metadata } from 'next'
+import Script from 'next/script'
 import { AdminI18nProvider } from '@/components/I18nProvider'
 import './globals.css'
 
@@ -9,9 +10,11 @@ export const metadata: Metadata = {
 
 export default function RootLayout({ children }: { children: React.ReactNode }) {
   return (
-    <html lang="en" className="dark" suppressHydrationWarning>
+    <html lang="ar" dir="rtl" className="dark" suppressHydrationWarning>
       <head>
-        <script
+        <Script
+          id="admin-theme-bootstrap"
+          strategy="beforeInteractive"
           dangerouslySetInnerHTML={{
             __html:
               "(function(){try{var m=document.cookie.match(/(?:^|; )rentaldrivego-theme=([^;]+)/);var theme=m?decodeURIComponent(m[1]):(localStorage.getItem('rentaldrivego-theme')||localStorage.getItem('admin-theme'));if(theme!=='light'&&theme!=='dark'){theme='dark'}document.documentElement.classList.remove('light','dark');document.documentElement.classList.add(theme);document.documentElement.style.colorScheme=theme;document.body&&document.body.setAttribute('data-theme',theme)}catch(e){}})();",
diff --git a/apps/admin/src/components/I18nProvider.tsx b/apps/admin/src/components/I18nProvider.tsx
index 95cfd84..26b20ca 100644
--- a/apps/admin/src/components/I18nProvider.tsx
+++ b/apps/admin/src/components/I18nProvider.tsx
@@ -109,10 +109,10 @@ type AdminI18nContext = {
 const Context = createContext<AdminI18nContext | null>(null)
 
 export function AdminI18nProvider({ children }: { children: React.ReactNode }) {
-  const [language, setLanguage] = useState<AdminLanguage>('en')
+  const [language, setLanguage] = useState<AdminLanguage>('ar')
   const [theme, setTheme] = useState<AdminTheme>('dark')
-  // Skip the very first write so we don't overwrite a stored preference with
-  // the default 'en' value before the hydration read-effect has applied it.
+  // Skip the very first write so we don't overwrite a stored preference before
+  // the hydration read-effect has applied it.
   const skipFirstLangWrite = useRef(true)
   const skipFirstThemeWrite = useRef(true)
 
diff --git a/apps/carplace/src/app/layout.tsx b/apps/carplace/src/app/layout.tsx
index 3eb018a..4a175f1 100644
--- a/apps/carplace/src/app/layout.tsx
+++ b/apps/carplace/src/app/layout.tsx
@@ -1,5 +1,6 @@
 import type { Metadata } from 'next'
 import { cookies } from 'next/headers'
+import Script from 'next/script'
 import CarplaceShell from '@/components/CarplaceShell'
 import { getCarplaceMessages } from '@/lib/carplace/messages'
 import { getCarplaceLanguage } from '@/lib/i18n.server'
@@ -36,8 +37,9 @@ export default async function RootLayout({ children }: { children: React.ReactNo
   return (
     <html lang={language} dir={language === 'ar' ? 'rtl' : 'ltr'} suppressHydrationWarning>
       <head>
-        {/* Runs before hydration to prevent flash of wrong theme */}
-        <script
+        <Script
+          id="carplace-theme-bootstrap"
+          strategy="beforeInteractive"
           dangerouslySetInnerHTML={{
             __html:
               "(function(){try{var m=document.cookie.match(/(?:^|; )rentaldrivego-theme=([^;]+)/);var theme=m?decodeURIComponent(m[1]):localStorage.getItem('rentaldrivego-theme');if(theme!=='light'&&theme!=='dark'){theme='dark'}document.documentElement.classList.toggle('dark',theme==='dark');document.documentElement.style.colorScheme=theme;document.body&&document.body.setAttribute('data-theme',theme)}catch(e){}})();",
diff --git a/apps/carplace/src/components/CarplaceShell.tsx b/apps/carplace/src/components/CarplaceShell.tsx
index 440e82c..e661229 100644
--- a/apps/carplace/src/components/CarplaceShell.tsx
+++ b/apps/carplace/src/components/CarplaceShell.tsx
@@ -118,15 +118,6 @@ export function getFooterContent(language: CarplaceLanguage): FooterContent {
   return footerLabels[language]
 }
 
-function detectBrowserLanguage(): CarplaceLanguage | null {
-  if (typeof navigator === 'undefined') return null
-  for (const language of Array.from(navigator.languages ?? [navigator.language])) {
-    const code = language.split('-')[0].toLowerCase()
-    if (isCarplaceLanguage(code)) return code
-  }
-  return null
-}
-
 type PreferencesContextValue = {
   language: CarplaceLanguage
   theme: Theme
@@ -145,7 +136,7 @@ export function useCarplacePreferences() {
 
 export default function CarplaceShell({
   children,
-  initialLanguage = 'en',
+  initialLanguage = 'ar',
   initialTheme = 'dark',
 }: {
   children: React.ReactNode
@@ -180,7 +171,7 @@ export default function CarplaceShell({
 
   useEffect(() => {
     const storedLanguage = readScopedPreference(SHARED_LANGUAGE_KEY)
-    const resolvedLanguage = isCarplaceLanguage(storedLanguage) ? storedLanguage : detectBrowserLanguage()
+    const resolvedLanguage = isCarplaceLanguage(storedLanguage) ? storedLanguage : 'ar'
     if (resolvedLanguage) setLanguageState(resolvedLanguage)
 
     const storedTheme = readScopedPreference(SHARED_THEME_KEY)
diff --git a/apps/carplace/src/lib/i18n.server.test.ts b/apps/carplace/src/lib/i18n.server.test.ts
index 93e3337..eb6d304 100644
--- a/apps/carplace/src/lib/i18n.server.test.ts
+++ b/apps/carplace/src/lib/i18n.server.test.ts
@@ -22,9 +22,9 @@ describe('getCarplaceLanguage', () => {
     await expect(getCarplaceLanguage()).resolves.toBe(language)
   })
 
-  it('defaults to English when the shared cookie is absent or invalid', async () => {
-    await expect(getCarplaceLanguage()).resolves.toBe('en')
+  it('defaults to Arabic when the shared cookie is absent or invalid', async () => {
+    await expect(getCarplaceLanguage()).resolves.toBe('ar')
     cookieValues.set(SHARED_LANGUAGE_COOKIE, 'es')
-    await expect(getCarplaceLanguage()).resolves.toBe('en')
+    await expect(getCarplaceLanguage()).resolves.toBe('ar')
   })
 })
diff --git a/apps/carplace/src/lib/i18n.server.ts b/apps/carplace/src/lib/i18n.server.ts
index 97b9dd8..8466929 100644
--- a/apps/carplace/src/lib/i18n.server.ts
+++ b/apps/carplace/src/lib/i18n.server.ts
@@ -3,5 +3,5 @@ import { SHARED_LANGUAGE_COOKIE, isCarplaceLanguage, type CarplaceLanguage } fro
 
 export async function getCarplaceLanguage(): Promise<CarplaceLanguage> {
   const cookieValue = (await cookies()).get(SHARED_LANGUAGE_COOKIE)?.value
-  return isCarplaceLanguage(cookieValue) ? cookieValue : 'en'
+  return isCarplaceLanguage(cookieValue) ? cookieValue : 'ar'
 }
diff --git a/apps/carplace/src/middleware.test.ts b/apps/carplace/src/middleware.test.ts
index 330be5b..4717ce9 100644
--- a/apps/carplace/src/middleware.test.ts
+++ b/apps/carplace/src/middleware.test.ts
@@ -42,8 +42,8 @@ describe('Carplace language bootstrap', () => {
 
   it.each([
     ['ar-MA,fr;q=0.8', 'ar'],
-    ['de-DE,fr-FR;q=0.7', 'fr'],
-    ['de-DE,es;q=0.9', 'en'],
+    ['de-DE,fr-FR;q=0.7', 'ar'],
+    ['de-DE,es;q=0.9', 'ar'],
   ])('resolves %s as %s', async (acceptLanguage, expected) => {
     const { proxy } = await import('./proxy')
     const response = proxy(request({ headers: { 'accept-language': acceptLanguage } }) as never) as any
diff --git a/apps/carplace/src/proxy.ts b/apps/carplace/src/proxy.ts
index e1987e6..25c4182 100644
--- a/apps/carplace/src/proxy.ts
+++ b/apps/carplace/src/proxy.ts
@@ -2,6 +2,7 @@ import { NextResponse } from 'next/server'
 import type { NextRequest } from 'next/server'
 
 const SHARED_LANGUAGE_COOKIE = 'rentaldrivego-language'
+const DEFAULT_LANGUAGE: Language = 'ar'
 
 type Language = 'en' | 'fr' | 'ar'
 
@@ -9,15 +10,6 @@ function isValidLanguage(value: string | null | undefined): value is Language {
   return value === 'en' || value === 'fr' || value === 'ar'
 }
 
-function detectFromAcceptLanguage(header: string | null): Language {
-  if (!header) return 'en'
-  for (const entry of header.split(',')) {
-    const code = entry.split(';')[0].trim().split('-')[0].toLowerCase()
-    if (isValidLanguage(code)) return code
-  }
-  return 'en'
-}
-
 export function proxy(request: NextRequest) {
   if (request.headers.has('x-middleware-subrequest')) {
     return new NextResponse('Unsupported internal request header', { status: 400 })
@@ -26,7 +18,7 @@ export function proxy(request: NextRequest) {
   const currentLanguage = request.cookies.get(SHARED_LANGUAGE_COOKIE)?.value
   if (isValidLanguage(currentLanguage)) return NextResponse.next()
 
-  const language = detectFromAcceptLanguage(request.headers.get('accept-language'))
+  const language = DEFAULT_LANGUAGE
   const requestHeaders = new Headers(request.headers)
   const existingCookies = request.headers.get('cookie') ?? ''
   const languageCookie = `${SHARED_LANGUAGE_COOKIE}=${language}`
diff --git a/apps/dashboard/src/app/layout.tsx b/apps/dashboard/src/app/layout.tsx
index b61f6e4..ed4a78a 100644
--- a/apps/dashboard/src/app/layout.tsx
+++ b/apps/dashboard/src/app/layout.tsx
@@ -25,7 +25,7 @@ export const metadata: Metadata = {
 }
 
 function resolveInitialLanguage(value: string | undefined): 'en' | 'fr' | 'ar' {
-  return value === 'fr' || value === 'ar' || value === 'en' ? value : 'en'
+  return value === 'fr' || value === 'ar' || value === 'en' ? value : 'ar'
 }
 
 export default async function RootLayout({ children }: { children: React.ReactNode }) {
diff --git a/apps/dashboard/src/app/public-auth-pages.test.ts b/apps/dashboard/src/app/public-auth-pages.test.ts
index 66d2194..8f298b6 100644
--- a/apps/dashboard/src/app/public-auth-pages.test.ts
+++ b/apps/dashboard/src/app/public-auth-pages.test.ts
@@ -86,7 +86,7 @@ describe("dashboard public auth pages", () => {
     const text = collectText(page).join(" ");
     const signInLink = findElement(
       page,
-      (element) => element.props.href === "/en/dark/sign-in",
+      (element) => element.props.href === "/ar/dark/sign-in",
     );
 
     expect(text).toContain("Invitation accepted");
diff --git a/apps/dashboard/src/components/I18nProvider.tsx b/apps/dashboard/src/components/I18nProvider.tsx
index 908c22e..41acbe4 100644
--- a/apps/dashboard/src/components/I18nProvider.tsx
+++ b/apps/dashboard/src/components/I18nProvider.tsx
@@ -1519,22 +1519,12 @@ const I18nContext = createContext<I18nContextValue | null>(null)
 const DASHBOARD_LANGUAGE_KEY = 'dashboard-language'
 
 function normalizeLanguage(value: string | null | undefined): DashboardLanguage {
-  return value === 'fr' || value === 'ar' || value === 'en' ? value : 'en'
-}
-
-function detectBrowserLanguage(): DashboardLanguage | null {
-  if (typeof navigator === 'undefined') return null
-  const langs = Array.from(navigator.languages ?? [navigator.language])
-  for (const lang of langs) {
-    const code = lang.split('-')[0].toLowerCase()
-    if (code === 'fr' || code === 'ar' || code === 'en') return code as DashboardLanguage
-  }
-  return null
+  return value === 'fr' || value === 'ar' || value === 'en' ? value : 'ar'
 }
 
 export function DashboardI18nProvider({
   children,
-  initialLanguage = 'en',
+  initialLanguage = 'ar',
 }: {
   children: React.ReactNode
   initialLanguage?: DashboardLanguage
@@ -1580,8 +1570,8 @@ export function DashboardI18nProvider({
       const next = normalizeLanguage(stored)
       if (next !== language) setLanguageState(next)
     } else {
-      const detected = detectBrowserLanguage()
-      if (detected && detected !== language) setLanguageState(detected)
+      const defaultLanguage = normalizeLanguage(null)
+      if (defaultLanguage !== language) setLanguageState(defaultLanguage)
     }
   }, [])
 
diff --git a/apps/dashboard/src/components/layout/DashboardAccessGuard.boundary.test.ts b/apps/dashboard/src/components/layout/DashboardAccessGuard.boundary.test.ts
index d9d62c3..769f1aa 100644
--- a/apps/dashboard/src/components/layout/DashboardAccessGuard.boundary.test.ts
+++ b/apps/dashboard/src/components/layout/DashboardAccessGuard.boundary.test.ts
@@ -135,8 +135,8 @@ describe('DashboardAccessGuard route helpers', () => {
   })
 
   it('builds sign-in redirects with public dashboard return paths', () => {
-    expect(buildSignInRedirect('/reservations')).toBe('/en/dark/sign-in?redirect=%2Fdashboard%2Freservations')
-    expect(buildSignInRedirect('/dashboard/fleet')).toBe('/en/dark/sign-in?redirect=%2Fdashboard%2Ffleet')
+    expect(buildSignInRedirect('/reservations')).toBe('/ar/dark/sign-in?redirect=%2Fdashboard%2Freservations')
+    expect(buildSignInRedirect('/dashboard/fleet')).toBe('/ar/dark/sign-in?redirect=%2Fdashboard%2Ffleet')
   })
 
   it('treats subscription as an owner-only recovery route independent of menu registration', () => {
diff --git a/apps/dashboard/src/lib/dashboardPaths.test.ts b/apps/dashboard/src/lib/dashboardPaths.test.ts
index 001f6ea..918b31e 100644
--- a/apps/dashboard/src/lib/dashboardPaths.test.ts
+++ b/apps/dashboard/src/lib/dashboardPaths.test.ts
@@ -21,8 +21,8 @@ describe('dashboard path normalization', () => {
   })
 
   it('builds the canonical homepage sign-in URL with a dashboard return path', () => {
-    expect(buildHomepageSignInPath('/reservations')).toBe('/en/dark/sign-in?redirect=%2Fdashboard%2Freservations')
+    expect(buildHomepageSignInPath('/reservations')).toBe('/ar/dark/sign-in?redirect=%2Fdashboard%2Freservations')
     expect(buildHomepageSignInPath('/dashboard/fleet', { locale: 'fr', theme: 'dark' })).toBe('/fr/dark/sign-in?redirect=%2Fdashboard%2Ffleet')
-    expect(buildHomepageSignInPath()).toBe('/en/dark/sign-in')
+    expect(buildHomepageSignInPath()).toBe('/ar/dark/sign-in')
   })
 })
diff --git a/apps/dashboard/src/lib/dashboardPaths.ts b/apps/dashboard/src/lib/dashboardPaths.ts
index 9718606..33da9eb 100644
--- a/apps/dashboard/src/lib/dashboardPaths.ts
+++ b/apps/dashboard/src/lib/dashboardPaths.ts
@@ -1,5 +1,5 @@
 const DASHBOARD_BASE_PATH = '/dashboard'
-const DEFAULT_SIGN_IN_LOCALE = 'en'
+const DEFAULT_SIGN_IN_LOCALE = 'ar'
 const DEFAULT_SIGN_IN_THEME = 'dark'
 
 export function toDashboardAppPath(path?: string | null): string {
diff --git a/apps/dashboard/src/proxy.test.ts b/apps/dashboard/src/proxy.test.ts
index 4985bb2..e690bd3 100644
--- a/apps/dashboard/src/proxy.test.ts
+++ b/apps/dashboard/src/proxy.test.ts
@@ -77,7 +77,7 @@ describe('dashboard proxy', () => {
 
     const response = proxy(request('http://dashboard:3001/dashboard/team') as never)
 
-    expect(response).toEqual({ kind: 'redirect', url: 'https://rentaldrivego.example/en/dark/sign-in?redirect=%2Fdashboard%2Fteam' })
+    expect(response).toEqual({ kind: 'redirect', url: 'https://rentaldrivego.example/ar/dark/sign-in?redirect=%2Fdashboard%2Fteam' })
   })
 
   it('redirects unprefixed internal app paths with a public dashboard return path', async () => {
@@ -85,7 +85,7 @@ describe('dashboard proxy', () => {
 
     const response = proxy(request('http://dashboard:3001/reservations') as never)
 
-    expect(response).toEqual({ kind: 'redirect', url: 'https://rentaldrivego.example/en/dark/sign-in?redirect=%2Fdashboard%2Freservations' })
+    expect(response).toEqual({ kind: 'redirect', url: 'https://rentaldrivego.example/ar/dark/sign-in?redirect=%2Fdashboard%2Freservations' })
   })
 
   it('ignores spoofed forwarded host/proto when building the dashboard sign-in redirect', async () => {
@@ -98,7 +98,7 @@ describe('dashboard proxy', () => {
       },
     }) as never)
 
-    expect(response).toEqual({ kind: 'redirect', url: 'https://market.example.com/en/dark/sign-in?redirect=%2Fdashboard%2Fbilling' })
+    expect(response).toEqual({ kind: 'redirect', url: 'https://market.example.com/ar/dark/sign-in?redirect=%2Fdashboard%2Fbilling' })
   })
 
   it('ignores internal forwarded hosts when building the dashboard sign-in redirect', async () => {
@@ -111,7 +111,7 @@ describe('dashboard proxy', () => {
       },
     }) as never)
 
-    expect(response).toEqual({ kind: 'redirect', url: 'https://market.example.com/en/dark/sign-in?redirect=%2Fdashboard%2Ffleet' })
+    expect(response).toEqual({ kind: 'redirect', url: 'https://market.example.com/ar/dark/sign-in?redirect=%2Fdashboard%2Ffleet' })
   })
 
   it('redirects legacy dashboard sign-in requests to the localized homepage sign-in route', async () => {
diff --git a/apps/dashboard/src/proxy.ts b/apps/dashboard/src/proxy.ts
index 6d038da..a8bbf78 100644
--- a/apps/dashboard/src/proxy.ts
+++ b/apps/dashboard/src/proxy.ts
@@ -4,7 +4,7 @@ import type { NextRequest } from 'next/server'
 const WEBSITE_URL = process.env.NEXT_PUBLIC_WEBSITE_URL ?? 'http://localhost:3000'
 const DASHBOARD_PUBLIC_URL = process.env.NEXT_PUBLIC_DASHBOARD_URL ?? `${WEBSITE_URL.replace(/\/$/, '')}/dashboard`
 const DASHBOARD_BASE_PATH = '/dashboard'
-const DEFAULT_SIGN_IN_LOCALE = 'en'
+const DEFAULT_SIGN_IN_LOCALE = 'ar'
 const DEFAULT_SIGN_IN_THEME = 'dark'
 
 function toDashboardAppPath(pathname: string): string {
diff --git a/apps/homepage/src/contracts/phase9/route-manifest.json b/apps/homepage/src/contracts/phase9/route-manifest.json
index 1d1aee8..f2655af 100644
--- a/apps/homepage/src/contracts/phase9/route-manifest.json
+++ b/apps/homepage/src/contracts/phase9/route-manifest.json
@@ -1,6 +1,6 @@
 {
   "version": "1.0",
-  "defaultLocale": "en",
+  "defaultLocale": "ar",
   "locales": ["en", "fr", "ar"],
   "rootDetection": true,
   "routes": [
@@ -82,7 +82,7 @@
   },
   "hreflang": {
     "values": ["en", "fr", "ar"],
-    "xDefaultLocale": "en",
+    "xDefaultLocale": "ar",
     "selfCanonical": true
   }
 }
diff --git a/apps/homepage/src/lib/localization/config.ts b/apps/homepage/src/lib/localization/config.ts
index 0c6eda8..d76f9d5 100644
--- a/apps/homepage/src/lib/localization/config.ts
+++ b/apps/homepage/src/lib/localization/config.ts
@@ -11,7 +11,7 @@ export type Locale = (typeof locales)[number];
 export type Direction = 'ltr' | 'rtl';
 export type RouteId = 'home' | 'sign-in' | 'forgot-password' | 'reset-password' | 'privacy' | 'terms' | 'accessibility';
 
-export const defaultLocale: Locale = 'en';
+export const defaultLocale: Locale = 'ar';
 export const defaultMode: ThemePreference = 'dark';
 export const localeCookie = 'hpc-locale';
 export const localeStorageKey = 'hpc.locale';
diff --git a/apps/homepage/src/proxy.ts b/apps/homepage/src/proxy.ts
index cdb2502..de0d3a4 100644
--- a/apps/homepage/src/proxy.ts
+++ b/apps/homepage/src/proxy.ts
@@ -5,7 +5,6 @@ import {
   isLocale,
   localeCookie,
   localeCookieMaxAgeSeconds,
-  localeFromAcceptLanguage,
   localizedModePath,
   routeIdFromAnyLocaleSlug,
   routeIdFromSlug,
@@ -47,11 +46,8 @@ function resolveApiOrigin(): string | undefined {
   return origins.size > 0 ? Array.from(origins).join(' ') : undefined;
 }
 
-function resolveRequestLocale(request: NextRequest) {
-  const cookieLocale = request.cookies.get(localeCookie)?.value;
-  return isLocale(cookieLocale)
-    ? cookieLocale
-    : localeFromAcceptLanguage(request.headers.get('accept-language')) || defaultLocale;
+function resolveRequestLocale() {
+  return defaultLocale;
 }
 
 function resolveRequestMode(request: NextRequest) {
@@ -69,6 +65,13 @@ function setLocaleCookie(response: NextResponse, locale: string): void {
     secure: process.env.NODE_ENV === 'production',
     httpOnly: false,
   });
+  response.cookies.set(dashboardLanguageCookie, locale, {
+    path: '/',
+    sameSite: 'lax',
+    maxAge: localeCookieMaxAgeSeconds,
+    secure: process.env.NODE_ENV === 'production',
+    httpOnly: false,
+  });
 }
 
 function setModeCookie(response: NextResponse, mode: string): void {
@@ -98,7 +101,7 @@ export function proxy(request: NextRequest): NextResponse {
   requestHeaders.set('Content-Security-Policy', csp);
 
   if (request.nextUrl.pathname === '/') {
-    const locale = resolveRequestLocale(request);
+    const locale = resolveRequestLocale();
     const mode = resolveRequestMode(request);
     const destination = request.nextUrl.clone();
     destination.pathname = `/${locale}/${mode}`;
@@ -110,11 +113,11 @@ export function proxy(request: NextRequest): NextResponse {
 
   const pathSegments = request.nextUrl.pathname.split('/').filter(Boolean);
 
-  // Redirect locale-less paths (e.g. /sign-in -> /en/dark/sign-in), but not proxied app paths or files.
+  // Redirect locale-less paths (e.g. /sign-in -> /ar/dark/sign-in), but not proxied app paths or files.
   const firstSegment = request.nextUrl.pathname.split('/')[1];
   const isFile = /\.\w+$/.test(request.nextUrl.pathname);
   if (firstSegment && !isFile && !isLocale(firstSegment) && !reservedProxySegments.has(firstSegment)) {
-    const locale = resolveRequestLocale(request);
+    const locale = resolveRequestLocale();
     const mode = resolveRequestMode(request);
     const destination = request.nextUrl.clone();
     destination.pathname = `/${locale}/${mode}${request.nextUrl.pathname}`;
diff --git a/apps/homepage/tests/browser/shell.spec.ts b/apps/homepage/tests/browser/shell.spec.ts
index a1a0980..2936177 100644
--- a/apps/homepage/tests/browser/shell.spec.ts
+++ b/apps/homepage/tests/browser/shell.spec.ts
@@ -35,7 +35,7 @@ for (const scenario of [
   });
 }
 
-test('root locale detection honors Accept-Language', async ({ browser }) => {
+test('root locale defaults to Arabic', async ({ browser }) => {
   const context = await browser.newContext({
     extraHTTPHeaders: { 'Accept-Language': 'ar;q=1,en;q=0.8' },
   });
diff --git a/apps/homepage/tests/unit/localization.test.ts b/apps/homepage/tests/unit/localization.test.ts
index b836691..cc7f9e8 100644
--- a/apps/homepage/tests/unit/localization.test.ts
+++ b/apps/homepage/tests/unit/localization.test.ts
@@ -16,7 +16,7 @@ describe('localization foundations', () => {
   it('selects a supported locale by quality', () => {
     expect(localeFromAcceptLanguage('de-DE;q=0.9, ar;q=0.8, fr;q=0.7')).toBe('ar');
     expect(localeFromAcceptLanguage('fr-CA, en;q=0.8')).toBe('fr');
-    expect(localeFromAcceptLanguage(null)).toBe('en');
+    expect(localeFromAcceptLanguage(null)).toBe('ar');
   });
 
   it('validates locale direction and route lookup', () => {
@@ -45,7 +45,7 @@ describe('localization foundations', () => {
     const links = hreflangMap(new URL('https://approved.test'), 'home');
     expect(links.en).toBe('https://approved.test/en/dark');
     expect(links.ar).toBe('https://approved.test/ar/dark');
-    expect(links['x-default']).toBe('https://approved.test/en/dark');
+    expect(links['x-default']).toBe('https://approved.test/ar/dark');
   });
 
   it('preserves only approved campaign query values and valid hashes', () => {
diff --git a/apps/homepage/tests/unit/proxy.test.ts b/apps/homepage/tests/unit/proxy.test.ts
index c5b772d..2905307 100644
--- a/apps/homepage/tests/unit/proxy.test.ts
+++ b/apps/homepage/tests/unit/proxy.test.ts
@@ -76,7 +76,7 @@ describe('homepage proxy app boundaries', () => {
 
     expect(response).toMatchObject({
       kind: 'redirect',
-      url: 'https://rentaldrivego.ma/fr/dark',
+      url: 'https://rentaldrivego.ma/ar/dark',
     });
   });
 
