fix: 修复 SDK 2.4.0 + WPF/WinForms 双开下的编译错误

dotnet 8.0.424 SDK + Microsoft.WindowsAppSDK 2.4.0 实测 build 通过(0 警告 0 错误)。

修复内容:

- csproj:TargetFramework 从 net8.0-windows 改为 net8.0-windows10.0.19041.0,新增 SupportedOSPlatformVersion=10.0.17763.0(WindowsAppSDK 2.4.0 强制要求 TFM 带 Windows 版本号)

- 4 个 Services 文件加 using System.IO(Logger/ConfigService/StateService/GotifyWebSocketService)。WPF+WinForms 双开项目模板不自动 import System.IO

- GotifyApiService 加 using System.Net.Http(同上,HttpClient 不在 implicit usings)

- App.xaml.cs:using Application = System.Windows.Application(WPF/WinForms Application 撞名)

- MainWindow.xaml.cs:using MessageBox = System.Windows.MessageBox(同上,MessageBox 撞名)

- App.xaml.cs:SendTestNotificationAsync 里 Date 从 .UtcNow.ToUnixTimeMilliseconds() 改回 .UtcNow(原 plan 写法有 bug,long 塞不进 DateTimeOffset)

- App.xaml.cs:OnNotificationInvoked 重写:WindowsAppSDK 2.4.0 把 args.Arguments 从 string 改成 IDictionary<string,string>,改用 TryGetValue("url", out var url) 取参数

- NotificationService:AddArgument 从单参 "url=escaped" 改成两参 ("url", url)。WindowsAppSDK 2.4.0 不再支持单参 "key=value" 写法

- GotifyWebSocketService:删除 _forceReconnect 字段(写了不读,改成 RequestReconnect 只调 socket.Abort 让外层 RunLoopAsync 自然重连)

App.xaml.cs

@@ -2,6 +2,9 @@ using System.Diagnostics;
 using System.Windows;
 using Microsoft.Windows.AppNotifications;
 
+// 双开 WPF + WinForms 时,Application 在两个命名空间都有,用别名强制走 WPF 的。
+using Application = System.Windows.Application;
+
 namespace WindowsGotify;
 
 public partial class App : Application
@@ -94,7 +97,7 @@ public partial class App : Application
                 Message = "Windows Gotify Agent 测试通知。",
                 Title = "Gotify 测试",
                 Priority = 5,
-                Date = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds()
+                Date = DateTimeOffset.UtcNow
             });
     }
 
@@ -106,10 +109,9 @@ public partial class App : Application
         {
             try
             {
-                var arguments = args.Arguments;
-                if (arguments.StartsWith("url=", StringComparison.OrdinalIgnoreCase))
+                // Windows App SDK 2.4.0:args.Arguments 已经是 IDictionary<string, string>,由 AddArgument(key, value) 注入
+                if (args.Arguments.TryGetValue("url", out var url) && !string.IsNullOrWhiteSpace(url))
                 {
-                    var url = Uri.UnescapeDataString(arguments[4..]);
                     Process.Start(new ProcessStartInfo
                     {
                         FileName = url,