Enable Arabic translation for login and registration across the platform

Adds Arabic translations for authentication-related keys in `ar.json` and removes unused components from `DashboardPage.tsx`.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: d7e7c4e8-20cb-41c4-9d0e-79f48938fede
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/9777c70b-fc38-4831-8d6b-78dfffe041b0/fce1a53e-5aa6-4e72-85f6-b7412c184f0c.jpg

client/src/i18n/locales/ar.json

@@ -39,6 +39,25 @@
     "logout": "تسجيل الخروج",
     "profile": "الملف الشخصي"
   },
+  "auth": {
+    "login": "تسجيل الدخول",
+    "register": "إنشاء حساب",
+    "signup": "إنشاء حساب",
+    "email": "البريد الإلكتروني",
+    "password": "كلمة المرور",
+    "confirmPassword": "تأكيد كلمة المرور",
+    "username": "اسم المستخدم",
+    "firstName": "الاسم الأول",
+    "lastName": "الاسم الأخير",
+    "forgotPassword": "نسيت كلمة المرور؟",
+    "createAccount": "إنشاء حساب جديد",
+    "alreadyHaveAccount": "لديك حساب بالفعل؟",
+    "dontHaveAccount": "ليس لديك حساب؟",
+    "loginSuccess": "تم تسجيل الدخول بنجاح",
+    "registerSuccess": "تم إنشاء الحساب بنجاح",
+    "invalidCredentials": "بيانات الدخول غير صحيحة",
+    "accountExists": "الحساب موجود بالفعل"
+  },
   "tasks": {
     "title": "المهام",
     "createTask": "إنشاء مهمة",

client/src/pages/DashboardPage.tsx

@@ -1,19 +1,18 @@
 import { useAuth } from "@/hooks/useAuth";
 import { useLocation } from "wouter";
 import { useEffect, useState } from "react";
-import Header from "@/components/layout/Header";
 import Sidebar from "@/components/layout/Sidebar";
 import TaskList from "@/components/tasks/TaskList";
 import FinancialOverview from "@/components/financial/FinancialOverview";
 import VoiceRecorder from "@/components/voice/VoiceRecorder";
 import VoiceIndicator from "@/components/voice/VoiceIndicator";
 import DailyJoke from "@/components/ai/DailyJoke";
-import { CommandPalette } from "@/components/CommandPalette";
 import { useVoiceContext } from "@/context/VoiceProvider";
 import { useNotifications } from "@/context/NotificationProvider";
 import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
 import { Button } from "@/components/ui/button";
 import { Badge } from "@/components/ui/badge";
+import { CardSkeleton, PageSkeleton } from "@/components/ui/loading-skeleton";
 import { 
   Calendar, 
   DollarSign,