feat: add legal tabs and update header assets

Switch the legal page to tabbed EULA/privacy content with URL sync, update header styling, and migrate footer icons to Ant Design.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tailwind.config.ts

@@ -0,0 +1,10 @@
+import type { Config } from "tailwindcss"
+import typography from "@tailwindcss/typography"
+
+export default {
+  content: ["./index.html", "./src/**/*.{js,ts,jsx,tsx}"],
+  theme: {
+    extend: {},
+  },
+  plugins: [typography],
+} satisfies Config