Add settings modal for theme and language customization

Introduces a new SettingsModal component allowing users to select themes (light, dark, system) and languages, saving preferences to localStorage. The modal is integrated into Home and Landing pages.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 069d4324-6c40-4355-955e-c714a50de1ea
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/3df548ff-50ae-432f-9be4-25d34eccc983/069d4324-6c40-4355-955e-c714a50de1ea/9tQ591o

client/src/pages/Home.tsx

@@ -6,6 +6,7 @@ import { useState } from "react";
 import MainContent from "@/components/MainContent";
 import LoginModal from "@/components/LoginModal";
 import SearchModal from "@/components/SearchModal";
+import SettingsModal from "@/components/SettingsModal";
 import { useToast } from "@/hooks/use-toast";
 import { queryClient } from "@/lib/queryClient";
 import { useLocation } from "wouter";
@@ -14,6 +15,7 @@ export default function Home() {
   const { user, isAuthenticated } = useAuth();
   const [isLoginModalOpen, setIsLoginModalOpen] = useState(false);
   const [isSearchModalOpen, setIsSearchModalOpen] = useState(false);
+  const [isSettingsModalOpen, setIsSettingsModalOpen] = useState(false);
   const { toast } = useToast();
   const [, setLocation] = useLocation();
 
@@ -120,6 +122,7 @@ export default function Home() {
                   <Button 
                     variant="ghost" 
                     size="sm"
+                    onClick={() => setIsSettingsModalOpen(true)}
                     data-testid="button-settings"
                   >
                     <Settings className="h-4 w-4" />
@@ -154,6 +157,12 @@ export default function Home() {
         isOpen={isSearchModalOpen}
         onClose={() => setIsSearchModalOpen(false)}
       />
+      
+      {/* Settings Modal */}
+      <SettingsModal
+        isOpen={isSettingsModalOpen}
+        onClose={() => setIsSettingsModalOpen(false)}
+      />
     </div>
   );
 }