feat: Add initial setup page and functionality for admin account creation

- Created setup.html for the initial configuration of the admin account.
- Implemented setup.js to handle form submission and validation.
- Added logo images for branding.
- Introduced storage.js for API data handling (load, save, remove).
- Added styles.css for consistent styling across the application.

login.js

@@ -0,0 +1,46 @@
+
+document.addEventListener('DOMContentLoaded', () => {
+    const loginForm = document.getElementById('loginForm');
+    const errorMessage = document.getElementById('error-message');
+
+    // Redirigir si ya está autenticado
+    fetch('/api/check-auth')
+        .then(res => res.json())
+        .then(data => {
+            if (data.isAuthenticated) {
+                window.location.href = '/';
+            }
+        });
+
+    loginForm.addEventListener('submit', async (e) => {
+        e.preventDefault();
+        errorMessage.style.display = 'none';
+
+        const username = document.getElementById('username').value;
+        const password = document.getElementById('password').value;
+
+        try {
+            const response = await fetch('/api/login', {
+                method: 'POST',
+                headers: {
+                    'Content-Type': 'application/json',
+                },
+                body: JSON.stringify({ username, password }),
+            });
+
+            if (response.ok) {
+                const data = await response.json();
+                // Guardar el rol del usuario para usarlo en la app principal
+                sessionStorage.setItem('userRole', data.role);
+                window.location.href = '/'; // Redirigir a la página principal
+            } else {
+                const errorData = await response.json();
+                errorMessage.textContent = errorData.error || 'Error al iniciar sesión.';
+                errorMessage.style.display = 'block';
+            }
+        } catch (error) {
+            errorMessage.textContent = 'No se pudo conectar con el servidor.';
+            errorMessage.style.display = 'block';
+        }
+    });
+});