Make the website interface support multiple languages for global accessibility

Implements i18n translations for Header component elements using `t` function and adds a missing translation in `ar.json`.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 5a4f78b4-6a2e-4391-b005-5544e086dac8
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/9777c70b-fc38-4831-8d6b-78dfffe041b0/c8675744-6bc9-4464-806b-f920c1471265.jpg

client/src/components/layout/Header.tsx

@@ -65,7 +65,7 @@ export default function Header() {
               href="/dashboard"
               className="transition-colors hover:text-foreground/80 text-foreground"
             >
-              Dashboard
+              {t('navigation.dashboard')}
             </Link>
           </nav>
         )}
@@ -77,7 +77,7 @@ export default function Header() {
           {/* Voice Status Indicator */}
           <div className="flex items-center space-x-2 bg-muted/50 px-3 py-1 rounded-full">
             <Activity className="w-3 h-3 text-green-500 animate-pulse" />
-            <span className="text-xs text-muted-foreground hidden sm:inline">Voice Ready</span>
+            <span className="text-xs text-muted-foreground hidden sm:inline">{t('voice.ready')}</span>
           </div>
 
           {/* Language Switcher */}
@@ -132,26 +132,26 @@ export default function Header() {
                 <DropdownMenuSeparator />
                 <DropdownMenuItem onClick={() => setLocation("/settings")}>
                   <Settings className="mr-2 h-4 w-4" />
-                  <span>Settings</span>
+                  <span>{t('navigation.settings')}</span>
                 </DropdownMenuItem>
                 <DropdownMenuItem onClick={() => setLocation("/profile")}>
                   <User className="mr-2 h-4 w-4" />
-                  <span>Profile</span>
+                  <span>{t('navigation.profile')}</span>
                 </DropdownMenuItem>
                 <DropdownMenuSeparator />
                 <DropdownMenuItem onClick={handleLogout}>
                   <LogOut className="mr-2 h-4 w-4" />
-                  <span>Log out</span>
+                  <span>{t('navigation.logout')}</span>
                 </DropdownMenuItem>
               </DropdownMenuContent>
             </DropdownMenu>
           ) : (
             <div className="flex items-center space-x-2">
               <Button variant="ghost" size="sm" onClick={() => setLocation("/login")}>
-                Sign In
+                {t('auth.login')}
               </Button>
               <Button size="sm" onClick={() => setLocation("/login")}>
-                Get Started
+                {t('auth.register')}
               </Button>
             </div>
           )}

client/src/i18n/locales/ar.json

@@ -234,7 +234,8 @@
     "voiceActivated": "مفعل صوتياً",
     "speakingRate": "معدل الكلام",
     "voicePitch": "نبرة الصوت",
-    "voiceVolume": "مستوى الصوت"
+    "voiceVolume": "مستوى الصوت",
+    "ready": "الصوت جاهز"
   },
   "settings": {
     "title": "الإعدادات",