Add localStorage username persistence for auto-login

index.html

@@ -250,6 +250,20 @@
         multiplayerClient.registerPlayer(username);
       }
 
+      // Change username
+      function changeUsername() {
+        // Clear saved username from localStorage
+        localStorage.removeItem('connect5_username');
+        
+        // Show username modal
+        const modal = document.getElementById('usernameModal');
+        if (modal) {
+          modal.classList.add('active');
+          // Clear the input field
+          document.getElementById('usernameInput').value = '';
+        }
+      }
+
       // Allow Enter key to submit username
       document.addEventListener('DOMContentLoaded', () => {
         const input = document.getElementById('usernameInput');

multiplayer.js

@@ -27,7 +27,17 @@ class MultiplayerClient {
         
         this.socket.on('connect', () => {
             console.log('✅ Connected to multiplayer server');
-            this.showUsernameModal();
+            
+            // Check if username is saved in localStorage
+            const savedUsername = localStorage.getItem('connect5_username');
+            if (savedUsername) {
+                console.log('Found saved username:', savedUsername);
+                // Auto-login with saved username
+                this.registerPlayer(savedUsername);
+            } else {
+                // Show username modal if no saved username
+                this.showUsernameModal();
+            }
         });
         
         this.socket.on('disconnect', () => {
@@ -103,6 +113,10 @@ class MultiplayerClient {
             this.playerId = data.player.id;
             this.username = data.player.username;
             
+            // Save username to localStorage for auto-login
+            localStorage.setItem('connect5_username', this.username);
+            console.log('Username saved to localStorage');
+            
             // Hide username modal
             const modal = document.getElementById('usernameModal');
             if (modal) {