Fix model switch schema updates

Pass the new optional reasoning summary field through generated model switch calls so .NET and Rust compile against the updated Copilot runtime schema.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Copilot

dotnet/src/Session.cs

@@ -1320,7 +1320,7 @@ await InvokeRpcAsync<object>(
     /// </example>
     public async Task SetModelAsync(string model, string? reasoningEffort, ModelCapabilitiesOverride? modelCapabilities = null, CancellationToken cancellationToken = default)
     {
-        await Rpc.Model.SwitchToAsync(model, reasoningEffort, modelCapabilities, cancellationToken);
+        await Rpc.Model.SwitchToAsync(model, reasoningEffort, reasoningSummary: null, modelCapabilities: modelCapabilities, cancellationToken: cancellationToken);
     }
 
     /// <summary>

rust/src/session.rs

@@ -483,6 +483,7 @@ impl Session {
         let request = ModelSwitchToRequest {
             model_id: model.to_string(),
             reasoning_effort: opts.reasoning_effort,
+            reasoning_summary: None,
             model_capabilities: opts.model_capabilities,
         };
         self.rpc().model().switch_to(request).await?;

rust/tests/e2e/rpc_session_state.rs

@@ -67,6 +67,7 @@ async fn should_call_session_rpc_model_switchto() {
                         model_id: "gpt-4.1".to_string(),
                         reasoning_effort: Some("high".to_string()),
                         model_capabilities: None,
+                        reasoning_summary: None,
                     })
                     .await
                     .expect("switch model");