Expand login customizer: background, colors, custom CSS

Extend Settings > Login (beyond the existing style toggle + logo) toward
Loginfy parity: background image or color, form-panel background, button/
focus-accent color, and a custom login CSS field — all dependent on
"Style login page" and all falling back to the original fixed dark theme
when unset. LoginStyle.php sanitizes colors via sanitize_hex_color(),
esc_url()s the background image, and appends custom CSS (</style> stripped).
Verified on wp-login.php.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

app/src/pages/settings/settingsConfig.js

@@ -150,6 +150,48 @@ export const settingsGroups = [
             type: 'image',
             label: 'Login logo',
             description: 'Replace the WordPress logo on the login screen.',
+            dependsOn: 'style_login',
+          },
+          {
+            key: 'login_bg_image',
+            type: 'image',
+            label: 'Background image',
+            description: 'Full-screen background for the login page. Overrides the background color below.',
+            dependsOn: 'style_login',
+          },
+          {
+            key: 'login_bg_color',
+            type: 'color',
+            label: 'Background color',
+            description: 'Solid background color for the login page (used when no background image is set).',
+            default: '#0f1420',
+            dependsOn: 'style_login',
+          },
+          {
+            key: 'login_form_bg',
+            type: 'color',
+            label: 'Form background',
+            description: 'Background color of the login form panel.',
+            default: '#1c2333',
+            dependsOn: 'style_login',
+          },
+          {
+            key: 'login_button_color',
+            type: 'color',
+            label: 'Button color',
+            description: 'Color of the primary “Log In” button and the field focus accent.',
+            default: '#4f7cff',
+            dependsOn: 'style_login',
+          },
+          {
+            key: 'login_custom_css',
+            type: 'textarea',
+            mono: true,
+            rows: 8,
+            label: 'Custom login CSS',
+            description: 'Extra CSS applied to the login screen, after Aurora’s own styles.',
+            placeholder: 'body.login { … }',
+            dependsOn: 'style_login',
           },
         ],
       },