Direct popup mode

Popup mode is the default for independently hosted web applications.

const keymaster = new KeymasterConnectClient({
  targetOrigin: keymasterDeploymentOrigin,
  mode: "popup"
});

The first connect() or request() call:

1. installs the message listener;
2. opens /protocol/v1/popup on the configured Keymaster origin;
3. waits for the popup's ready message;
4. begins request/result traffic.

The SDK reuses the same named Session Window. Call the first operation from a click or another user activation so popup blockers permit it.

close() closes a popup owned by the SDK, rejects pending local promises, and removes browser listeners. It does not call connect.logout implicitly.