Settings Page

Build a settings page in Angular with three sub-sections accessible via nested navigation:

1. Profile (/settings/profile) -- displays a form with name and email fields, with a save button.
2. Notifications (/settings/notifications) -- displays toggles for email notifications, push notifications, and weekly digest.
3. Security (/settings/security) -- displays a change-password form with current password, new password, and confirm password fields.

The settings page should have a sidebar or tab navigation that highlights the active sub-section. The default route /settings should redirect to /settings/profile.

Each sub-section is its own component. The settings page component provides the layout with the navigation and a router outlet for the child content.

Output

Produce TypeScript files in a src/app/ directory:

• src/app/settings/settings.routes.ts -- route configuration for settings and its children
• src/app/settings/settings.component.ts -- layout component with navigation and router outlet
• src/app/settings/profile/profile.component.ts -- profile form sub-section
• src/app/settings/notifications/notifications.component.ts -- notification toggles sub-section
• src/app/settings/security/security.component.ts -- change password form sub-section

Do not include test files or build configuration.