chore: initial commit Dutra Store POS app

lib/screens/scan_screen.dart

@@ -0,0 +1,54 @@
+import 'package:flutter/material.dart';
+import 'package:mobile_scanner/mobile_scanner.dart';
+
+class ScanScreen extends StatefulWidget {
+  final String title;
+
+  const ScanScreen({
+    super.key,
+    required this.title,
+  });
+
+  @override
+  State<ScanScreen> createState() => _ScanScreenState();
+}
+
+class _ScanScreenState extends State<ScanScreen> {
+  final MobileScannerController _controller = MobileScannerController();
+  bool _isScanned = false;
+
+  void _handleBarcode(BarcodeCapture capture) {
+    if (_isScanned) return;
+
+    final barcode = capture.barcodes.firstOrNull;
+    if (barcode != null && barcode.rawValue != null) {
+      final code = barcode.rawValue!.trim();
+      if (code.isNotEmpty) {
+        _isScanned = true;
+        _controller.stop();
+        Navigator.pop(context, code);
+      }
+    }
+  }
+
+  @override
+  void dispose() {
+    _controller.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(widget.title),
+        centerTitle: true,
+      ),
+      body: MobileScanner(
+        controller: _controller,
+        onDetect: _handleBarcode,
+      ),
+    );
+  }
+}
+