feat: establish frontend foundation

src/app/ui/App.tsx

@@ -0,0 +1,22 @@
+import { MantineProvider } from "@mantine/core";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { BrowserRouter } from "react-router";
+
+import { AppRoutes } from "../routes";
+import { theme } from "../theme";
+
+const queryClient = new QueryClient({
+	defaultOptions: { queries: { refetchOnWindowFocus: false } },
+});
+
+export function App() {
+	return (
+		<MantineProvider theme={theme} forceColorScheme="light">
+			<QueryClientProvider client={queryClient}>
+				<BrowserRouter>
+					<AppRoutes />
+				</BrowserRouter>
+			</QueryClientProvider>
+		</MantineProvider>
+	);
+}