refactor: migrate from MUI to Ant Design for layout and components

- Updated package.json to remove MUI dependencies and add Ant Design.
- Refactored App component to use Ant Design's Layout, Header, Footer, and Sidebar.
- Created new Footer, Header, and Sidebar components using Ant Design.
- Removed old Header component that used MUI.
- Updated Home component to use Ant Design's Typography and Button.
- Added global styles in index.less and theme styles in theme.less and layout.less.
- Removed MUI theme configuration and replaced it with Ant Design's theming.

frontend/src/theme/theme.less

@@ -0,0 +1,15 @@
+// Dark theme colors
+@primary-color: #1DA57A;
+@text-color: #ffffff;
+@text-color-secondary: #bfbfbf;
+@heading-color: #ffffff;
+@body-background: #141414;
+@component-background: #1f1f1f;
+@border-color-base: #434343;
+@border-radius-base: 8px;
+@font-size-base: 14px;
+@menu-dark-bg: #1f1f1f;
+@menu-dark-submenu-bg: #1a1a1a;
+@layout-header-background: #1f1f1f;
+@font-size-header: 24px;
+@font-size-slider: 18px;