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/Controller.php

@@ -1,11 +1,12 @@
 <?php namespace App\Http\Controllers;
 
-use Illuminate\Foundation\Bus\DispatchesCommands;
 use Illuminate\Routing\Controller as BaseController;
+use Illuminate\Foundation\Bus\DispatchesJobs;
 use Illuminate\Foundation\Validation\ValidatesRequests;
+use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 
 abstract class Controller extends BaseController {
 
-	use DispatchesCommands, ValidatesRequests;
+	use AuthorizesRequests, DispatchesJobs, ValidatesRequests;
 
 }