Add ability for client to resume session (#1029)

src/ModelContextProtocol.Core/Client/ResumeClientSessionOptions.cs

@@ -0,0 +1,29 @@
+using ModelContextProtocol.Protocol;
+
+namespace ModelContextProtocol.Client;
+
+/// <summary>
+/// Provides the metadata captured from a previous MCP client session that is required to resume it.
+/// </summary>
+public sealed class ResumeClientSessionOptions
+{
+    /// <summary>
+    /// Gets or sets the server capabilities that were negotiated during the original session setialization.
+    /// </summary>
+    public required ServerCapabilities ServerCapabilities { get; set; }
+
+    /// <summary>
+    /// Gets or sets the server implementation metadata that identifies the connected MCP server.
+    /// </summary>
+    public required Implementation ServerInfo { get; set; }
+
+    /// <summary>
+    /// Gets or sets any instructions previously supplied by the server.
+    /// </summary>
+    public string? ServerInstructions { get; set; }
+
+    /// <summary>
+    /// Gets or sets the protocol version that was negotiated with the server.
+    /// </summary>
+    public string? NegotiatedProtocolVersion { get; set; }
+}