feat: integrate Spatie Media Library (#4)

- Added Spatie Media Library
- Added media library configuration file
- Updated Entry model to support media handling
- Added featured image upload with gallery selection and preview
- Added login tests with Dusk for user authentication
- Added Dusk test for featured image selection

Co-authored-by: jon brookes <marshyon@gmail.com>
Reviewed-on: https://codeberg.org/headshed/share-lt/pulls/4

config/app.php

@@ -123,4 +123,6 @@ return [
         'store' => env('APP_MAINTENANCE_STORE', 'database'),
     ],
 
+    'admin_email' => env('ADMIN_EMAIL', ''),
+
 ];