callServerTool: opt into progress-based timeout reset (#600)

A host may interpose a long-running or user-interactive step between the
guest's tools/call and the server's response. Without this, the base
SDK's default request timeout in Protocol.request() fires and the guest
sees -32001 even though the host is still working.

Passing onprogress causes Protocol.request to include _meta.progressToken
in the outgoing request and register a progress handler;
resetTimeoutOnProgress makes incoming notifications/progress reset the
per-request timer. Hosts can then heartbeat during long-running steps.
Callers can still override both.

src/app.ts

@@ -860,7 +860,14 @@ export class App extends ProtocolWithEvents<
     return await this.request(
       { method: "tools/call", params },
       CallToolResultSchema,
-      options,
+      {
+        // Hosts may interpose long-running or user-interactive steps before the
+        // tool result arrives. Opting in here lets a host heartbeat keep the
+        // request alive past the default timeout; callers can still override.
+        onprogress: () => {},
+        resetTimeoutOnProgress: true,
+        ...options,
+      },
     );
   }