feat: trigger actual Steam desktop login window via protocol handler for native account addition

frontend/src/pages/Dashboard.tsx

@@ -34,7 +34,7 @@ const Dashboard: React.FC = () => {
   const { currentTheme, setTheme } = useAppTheme();
   const { 
     accounts, isLoading, isSyncing, serverConfig, deleteAccount, 
-    switchAccount, openSteamLogin, updateServerConfig, loginToServer, syncNow
+    switchAccount, openSteamAppLogin, openSteamLogin, updateServerConfig, loginToServer, syncNow
   } = useAccounts();
   
   const [searchTerm, setSearchTerm] = useState('');
@@ -104,7 +104,7 @@ const Dashboard: React.FC = () => {
               variant="contained"
               color="primary"
               startIcon={<AddIcon />}
-              onClick={() => openSteamLogin('')}
+              onClick={() => openSteamAppLogin()}
               sx={{ height: 32 }}
             >
               Add