feat(dev): environment ribbon and one-click dev login on the public site and auth pages

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

includes/auth_header.php

@@ -65,6 +65,7 @@ $app_name   = defined('APP_NAME') ? APP_NAME : 'FitMe 3070';
         /* 16px inputs stop iOS from auto-zooming on focus */
         @media (max-width: 575.98px) { .form-control { font-size: 16px; } .auth-card { padding: 1.5rem; } }
     </style>
+<?php include __DIR__ . '/env_ribbon.php';   // moldura de aviso fora de produção ?>
 </head>
 <body>
 <main class="auth-card">