Add more Gray-Scott regimes

[kosmickroma]

What

Add more named (f, k) parameter pairs to the GS_REGIMES dict in gs/engine.py.

Why

More regimes = more visual variety. We currently have 15 from Pearson's 1993 catalog. The full xmorphia catalog has
many more unexplored regions of parameter space.

How

Open gs/engine.py and add entries to GS_REGIMES:

"regime_name": (f_value, k_value),

Resources

- http://www.mrob.com/pub/comp/xmorphia/index.html — full parameter map with visual previews
- Pearson, J.E. (1993) — "Complex Patterns in a Simple System"
- Try values in the range f: 0.01–0.08, k: 0.04–0.07 for interesting results

Notes

- Test by running python main.py and hitting S to cycle until your regime appears
- Describe what the pattern looks like in your PR so we can name it well
- Even unstable or weird ones are interesting — add them