[WIP] Update urchin refinement to use last two coefficients in tail estimation

[Copilot]

• Change n_tail_orders from 1 if warped_mesh.dim > 1 else 2 to 2 in warp_and_refine_until_resolved() in meshmode/mesh/generation.py
• Run tests to validate the change (urchin generation succeeds)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Use the last two coefficients in tail estimation in urchin refinement</issue_title>
<issue_description></issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Use the last two coefficients in tail estimation in urchin refinement #491

---

🔒 GitHub Advanced Security automatically protects Copilot coding agent pull requests. You can protect all pull requests by enabling Advanced Security for your repositories. Learn more about Advanced Security.