feat: PluginIsolation 新增进程内 IPC 传输（InProcPluginIpcTransport）

LanMountainDesktop.PluginIsolation.Ipc/InProcPluginIpcTransport.cs

@@ -0,0 +1,74 @@
+namespace LanMountainDesktop.PluginIsolation.Ipc;
+
+/// <summary>
+/// 进程内 IPC 传输。将 <see cref="PluginIpcClient"/> 的调度委托直接绑定到
+/// <see cref="PluginIpcServer"/> 的处理入口，不经过命名管道。
+/// 用于不支持子进程/命名管道的平台（如 Android），插件契约与序列化路径保持不变：
+/// 请求仍会经过 JsonElement 序列化/反序列化边界，与管道传输行为一致。
+/// </summary>
+public sealed class InProcPluginIpcTransport : IDisposable
+{
+    private readonly PluginIpcClient _client;
+    private volatile bool _disposed;
+
+    private InProcPluginIpcTransport(PluginIpcClient client, PluginIpcServer server)
+    {
+        _client = client;
+        Server = server;
+
+        client.RequestDispatcher = (route, payload, cancellationToken) =>
+        {
+            ThrowIfDisposed();
+            return server.HandleRequestAsync(route, payload, cancellationToken);
+        };
+
+        client.NotificationDispatcher = (route, payload, cancellationToken) =>
+        {
+            ThrowIfDisposed();
+            return server.HandleNotificationAsync(route, payload, cancellationToken);
+        };
+    }
+
+    /// <summary>
+    /// 绑定后的服务端。
+    /// </summary>
+    public PluginIpcServer Server { get; }
+
+    /// <summary>
+    /// 绑定后的客户端。请求/通知将直接分发到 <see cref="Server"/>。
+    /// </summary>
+    public PluginIpcClient Client => _client;
+
+    /// <summary>
+    /// 将客户端与服务端以进程内直通方式连接。
+    /// </summary>
+    /// <param name="client">插件侧客户端</param>
+    /// <param name="server">宿主侧服务端</param>
+    /// <returns>传输句柄；Dispose 后客户端调度将抛出 <see cref="ObjectDisposedException"/>。</returns>
+    public static InProcPluginIpcTransport Connect(PluginIpcClient client, PluginIpcServer server)
+    {
+        ArgumentNullException.ThrowIfNull(client);
+        ArgumentNullException.ThrowIfNull(server);
+        return new InProcPluginIpcTransport(client, server);
+    }
+
+    /// <summary>
+    /// 断开传输。之后客户端的请求/通知将失败。
+    /// </summary>
+    public void Dispose()
+    {
+        if (_disposed)
+        {
+            return;
+        }
+
+        _disposed = true;
+        _client.RequestDispatcher = null;
+        _client.NotificationDispatcher = null;
+    }
+
+    private void ThrowIfDisposed()
+    {
+        ObjectDisposedException.ThrowIf(_disposed, this);
+    }
+}