Wire global styles into React root layout

Imports index.scss, primereact.min.css, and primeicons.css in the
root layout so all global styles apply across the entire app.

src/routes/layout.tsx

@@ -6,6 +6,11 @@ import { createRootLogger } from "@/observability/logger/root";
 import { ApiClientProvider } from "@/shared/api/provider";
 import { ApiClient } from "@/shared/api/client";
 
+// Global styles
+import "@/styles/index.scss";
+import "primereact/resources/primereact.min.css";
+import "primeicons/primeicons.css";
+
 /**
  * Root layout — wraps the entire app with global providers.
  * Uses <Outlet /> (not {children}) because Modern.js uses React Router

src/styles/index.scss

@@ -0,0 +1,20 @@
+// Global styles entry point for the React app
+// Import order matches the Angular app's styles.scss
+
+@import 'reset';
+@import 'font-faces';
+@import 'colors';
+@import 'variables';
+@import 'fonts';
+@import 'fonts.classes';
+@import 'shadows';
+@import 'screen';
+@import 'layouts';
+@import 'mixins';
+@import 'layout';
+@import 'prime-styles';
+@import 'prime-calendar';
+@import 'icons';
+@import 'buttons';
+@import 'common';
+@import 'overrides';