K2GO-434 refactor(setup): extract the provisioning pipeline loop to a controller

Move the readyPoll loop + orchestrateStep + the pipeline latch state out of
SetupProgressActivity into SetupProgressController (Activity-scoped, driven
through a narrow Host); render() and the *InSession/prootActive predicates
read the latches back through getters. Behavior-preserving.

Author: luisguzman-adfa