add progress indicator for model loading

this takes a significant amount of time for big models. currently only queued is displayed which is confusing

Start by locating the model-loading entry point and the code that currently displays the queued state. Trace how loading status is reported for large models and determine where a progress indicator can be surfaced. Done means users can distinguish ongoing model loading from a queued job and see its progress.

Written by the indexing model from the issue text.