test(android app): this is the start to the android app

mobileLst/components/HiddenScanner.tsx

@@ -0,0 +1,41 @@
+import React, { useEffect, useRef, useState } from "react";
+import { Text, TextInput, View } from "react-native";
+
+export default function HiddenScannerListener({ onScan }: { onScan: any }) {
+	const [buffer, setBuffer] = useState("");
+	const inputRef = useRef<TextInput>(null);
+
+	// Keep focusing the invisible input
+	useEffect(() => {
+		const timer = setInterval(() => {
+			if (inputRef.current) inputRef.current.focus();
+		}, 500);
+		return () => clearInterval(timer);
+	}, []);
+
+	const handleChange = (text: string) => {
+		// Most scanners append '\n' (Enter) or '\t'; trim and send
+		if (text.endsWith("\n") || text.endsWith("\t")) {
+			const code = text.trim();
+			if (code) onScan?.(code);
+			setBuffer("");
+		} else {
+			setBuffer(text);
+		}
+	};
+
+	return (
+		<TextInput
+			ref={inputRef}
+			value={buffer}
+			onChangeText={handleChange}
+			autoFocus
+			style={{
+				position: "absolute",
+				opacity: 0, // invisible
+				height: 0, // takes no space
+				width: 0,
+			}}
+		/>
+	);
+}