Optionaloptions: BrowserlessCreateSessionOptionsThe resolved provider/session configuration (region, credential refs already resolved
upstream). May be undefined when the provider carries no configuration.
The Browserless client the driver creates its session with.
A factory that constructs an IBrowserlessClient for a session — the creation seam. Production supplies a factory that builds the real browserless.io adapter from resolved config; tests supply one that returns a
FakeBrowserlessClient.