acsicuib/YAFS ? reverse-engineered prompt

Build me a Python simulator for fog and IoT scenarios, like the YAFS project. I want to be able to model a network of devices, links, sensors, and edge nodes, then run experiments where the topology can change during the simulation, new message sources can appear, and placement decisions can be updated while it is running.

Please make it easy to define a scenario and run it from simple example scripts, with a few tutorial style demos for basic simulation, service movement, topology changes, and user movement. The results should be saved in a simple raw format that is easy to analyze later, and it would be great if the project also supports generating network plots over time so I can turn them into an animation.

Use Python 3.12 and keep it friendly for people who want to extend the placement and orchestration logic themselves. If you need to, look up current docs online for any details.