Sanitize fire time-hull mesh inputs to prevent disappearing Plotly meshes

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Motivation

• Users observed fire_plot renders that disappear when the Plotly scene is interacted with, which is consistent with unstable WebGL behavior caused by non-finite mesh arrays.
• The intent is to make plot_climate_filled_hull robust to imperfect hull geometry (NaNs or invalid triangle references) so visualizations remain stable.

Description

• Add _sanitize_mesh_inputs to plot_climate_filled_hull which drops vertices with non-finite coordinates or per-vertex times, remaps triangle indices after compaction, and discards triangles that reference removed or out-of-bounds vertices, with clear errors if nothing renderable remains.
• Run sanitization before building the vertex->slice mapping so climate scalar coloring stays aligned with surviving vertices.
• Add a regression test test_plot_climate_filled_hull_drops_nonfinite_vertices_and_remaps_tris that injects a NaN vertex and asserts the produced Mesh3d arrays are finite, in-bounds, and that intensity length matches the surviving vertex count.

Testing

• Ran the focused viewer/scalar tests with pytest tests/test_fire_hull_viewer_scalars.py -q which passed.
• Ran additional smoke/regression tests with pytest tests/test_fire_plot_cube_first.py tests/test_gridmet_safety.py -q which passed.
• All executed automated tests completed successfully (all tests run in this rollout passed).

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Codex Task