feat(companion): initial rn port scaffold

aris/app/(tabs)/stocks.tsx

@@ -0,0 +1,22 @@
+import { View } from "react-native";
+
+import { Container } from "@/components/Container";
+import { Text } from "@/components/ui/text";
+
+export default function StocksScreen() {
+	return (
+		<View className={styles.container}>
+			<Container>
+				<Text variant="h3">Stocks</Text>
+				<Text className={styles.subtitle}>
+					Port of SwiftUI StockSettingsView will live here.
+				</Text>
+			</Container>
+		</View>
+	);
+}
+
+const styles = {
+	container: "flex flex-1 bg-white",
+	subtitle: "mt-2 text-sm text-muted-foreground",
+};