Add induction demo playback support to Flask GUI

[lpurdy01]

Summary

• add CLI field-map tracking and timeline playback to the Flask GUI, ensuring visualization frames persist and downloads cover generated CSVs
• publish an induction motor demo scenario plus DXF assets and document the end-to-end workflow in the user guide
• update implementation notes, agent guidance, and site navigation to surface the new animation controls and tutorial

Testing

• pytest tests/test_gui_flask.py

---

Codex Task