feat: add device and background services

lib/services/device_service.dart

@@ -0,0 +1,65 @@
+import 'package:flutter/services.dart';
+import 'package:path_provider/path_provider.dart';
+import 'dart:io';
+
+class DeviceService {
+  static const _channel = MethodChannel('xyz.nuark.update_forge_companion/device');
+
+  Future<String?> getInstalledVersion(String packageName) async {
+    try {
+      final result = await _channel.invokeMethod<String>(
+        'getInstalledVersion',
+        {'packageName': packageName},
+      );
+      return result;
+    } on PlatformException {
+      return null;
+    }
+  }
+
+  Future<bool> installApk(String filePath) async {
+    try {
+      final result = await _channel.invokeMethod<bool>(
+        'installApk',
+        {'filePath': filePath},
+      );
+      return result ?? false;
+    } on PlatformException {
+      return false;
+    }
+  }
+
+  Future<bool> openApp(String packageName) async {
+    try {
+      final result = await _channel.invokeMethod<bool>(
+        'openApp',
+        {'packageName': packageName},
+      );
+      return result ?? false;
+    } on PlatformException {
+      return false;
+    }
+  }
+
+  Future<String> downloadFile({
+    required Stream<List<int>> stream,
+    required int? contentLength,
+    required String fileName,
+    void Function(int received, int? total)? onProgress,
+  }) async {
+    final dir = await getTemporaryDirectory();
+    final file = File('${dir.path}/$fileName');
+    final sink = file.openWrite();
+
+    int received = 0;
+    await for (final chunk in stream) {
+      sink.add(chunk);
+      received += chunk.length;
+      onProgress?.call(received, contentLength);
+    }
+    await sink.flush();
+    await sink.close();
+
+    return file.path;
+  }
+}