fix: WP-Admin CSS conflicts and add-to-cart redirect

- Fix CSS conflicts between WP-Admin and SPA (radio buttons, chart text)
- Add Tailwind important selector scoped to #woonoow-admin-app
- Remove overly aggressive inline SVG styles from Assets.php
- Add targeted WordPress admin CSS overrides in index.css
- Fix add-to-cart redirect to use woocommerce_add_to_cart_redirect filter
- Let WooCommerce handle cart operations natively for proper session management
- Remove duplicate tailwind.config.cjs

admin-spa/tailwind.config.js

@@ -1,6 +1,7 @@
 /** @type {import('tailwindcss').Config} */
 module.exports = {
   darkMode: ["class"],
+  important: '#woonoow-admin-app',
   content: ["./src/**/*.{ts,tsx,css}", "./components/**/*.{ts,tsx,css}"],
   theme: {
     container: { center: true, padding: "1rem" },