Add Stability-Based Coloring to Embedding Visualization

[smglsn12]

Summary

This PR updates the embedding visualization so that structures are color-coded by their stability classification (stable, metastable, unstable). This enhances the interpretability of the embedding view and allows potential clustering by stable and metastable structures.

Details

• Updated the embedding visualization to assign colors based on each structure’s stability category.
• Introduced a requirement that all Structure objects include stability information within their properties attribute.
  • This stability metadata can be provided directly (if precomputed), or
  • It can be generated by running the stability metrics as a part of the run_benchmark call.

Impact

These changes improve the clarity and utility of the embedding plots, especially when comparing or filtering structures by stability. Users will need to ensure that stability metadata is available for each structure before generating visualizations.

[andaero]

This makes sense to me! I think the main thing I would add is an additional color specifically for S.U.N. or M.S.U.N. crystals.

Separately, although it is likely out of scope for this pr, it would be useful to only plot crystals that fall into these different buckets (stable, metastable, sun, msun) rather than plotting all generated crystals.

[andaero]

Left comments above already! Otherwise lgtm!