Fix Laravel 5.5 compatibility issues - view helpers, collections, and auth routes

- Replace {{ url() }} with {{ url('/') }} in all blade templates to fix object-to-string conversion errors
- Update TeamStoreModel::selectTeamStoreGroupByCartKey() to use first() instead of get() for Laravel 5.5 Collections
- Fix TeamStoreController to access object properties directly instead of using array syntax [0]
- Update authentication routes to use Laravel 5.5 method names (showLoginForm, login, logout)
- Update login/register links from /auth/login to /login throughout views (navbar, app, auth pages)
- Verify cart, login, and register pages working with HTTP 200 status

app/Http/Controllers/teamstore/TeamStoreController.php

@@ -591,7 +591,7 @@ class TeamStoreController extends Controller
 		//var_dump($items_group);
 		$grouped_item 	= $m->selectTeamStoreGroupByCartKey($cartKey);
 		if ($grouped_item) {
-			$defId = $grouped_item[0]->StoreId;
+			$defId = $grouped_item->StoreId;
 		} else {
 			$defId = 0;
 		}