Add Windows runner files for high DPI support and console output

- Created runner.exe.manifest to enable DPI awareness and dark mode support.
- Implemented utility functions in utils.cpp and utils.h for console creation and command line argument handling.
- Developed Win32Window class in win32_window.cpp and win32_window.h to manage high DPI-aware windows, including theme updates and message handling.

lib/platform/window_state_io.dart

@@ -0,0 +1,30 @@
+import 'dart:ui';
+
+import 'package:shared_preferences/shared_preferences.dart';
+
+class WindowStateStore {
+  WindowStateStore._();
+
+  static final WindowStateStore instance = WindowStateStore._();
+
+  static const String _widthKey = 'window_width';
+  static const String _heightKey = 'window_height';
+
+  Future<Size?> loadWindowSize() async {
+    final SharedPreferences prefs = await SharedPreferences.getInstance();
+    final double? width = prefs.getDouble(_widthKey);
+    final double? height = prefs.getDouble(_heightKey);
+
+    if (width == null || height == null) {
+      return null;
+    }
+
+    return Size(width, height);
+  }
+
+  Future<void> saveWindowSize(Size size) async {
+    final SharedPreferences prefs = await SharedPreferences.getInstance();
+    await prefs.setDouble(_widthKey, size.width);
+    await prefs.setDouble(_heightKey, size.height);
+  }
+}