In comfyui internals, 'prompt` actually refers to an entire set of nodes and settings. Previously, we were hijacking the `recursive_output_delete_if_changed` call, but a recent change in comfyui has switched this behavior to the class `IsChangedCache`. The hook in place before had more to do with detecting bugs to do with caching than anything else, so I've implemented a similar sort of hijack for `IsChangedCache`.

The presence of the key `output` in `data` during `send_sync` calls was enough to assert `data["output"]["images"]` was present and populated (i.e., we are post-inference and receiving the final images from comfyui). However, comfyui internals have changed so that `data["output"]["images"]` can be equal to `None` in ordinary circumstances during other stages of generation. As such, I have changed the logic to check for the key and for non-`None` values.