chore: configure Google OAuth environment variables, update API proxy settings, and ignore .env files

frontend/src/components/layout/Header.jsx

@@ -28,7 +28,7 @@ export default function Header() {
         <Link to="/" className="flex items-center gap-3 hover:opacity-80 transition-opacity whitespace-nowrap">
           <img src="/favicon.svg" alt="Deck of Cards Logo" className="w-10 h-10 shadow-sm rounded-xl object-contain" />
           <span className="text-2xl font-black bg-clip-text text-transparent bg-gradient-to-r from-blue-600 to-indigo-600 hidden sm:block">
-            Deck of Cardssss
+            Deck of Cards
           </span>
         </Link>
 

frontend/vite.config.js

@@ -10,6 +10,12 @@ export default defineConfig({
   ],
   server: {
     host: '0.0.0.0',
-    allowedHosts: true
+    allowedHosts: true,
+    proxy: {
+      '/api': {
+        target: process.env.BACKEND_URL || 'http://backend:8000',
+        changeOrigin: true
+      }
+    }
   }
 })