geodesic_grid: fix undefined variable in _triangle_index neighbor-umbrella path

[aryanputta]

Problem

_triangle_index in geodesic_grid.py calls _from_neighbor_umbrella with four arguments:

return _from_neighbor_umbrella(umbrella, v, w, inclusive)

inclusive is never defined anywhere in _triangle_index. Running this path raises a NameError at runtime. Additionally, _from_neighbor_umbrella (line 204) only accepts three parameters (idx, v, u), so even if inclusive were defined the call would raise a TypeError.

Flake8 also flags this as F821 (undefined name).

Closes #1607

Fix

Remove the spurious inclusive argument so the call matches the function signature:

return _from_neighbor_umbrella(umbrella, v, w)

Testing

Ran the existing geodesic grid unit tests locally -- all pass. The neighbor-umbrella path in _triangle_index now executes without error.

Checklist

• Code change is real and addresses a runtime bug
• - [x] No unrelated formatting or whitespace changes
• - [x] No AI used