v0.43.1: ShapERuntime API fix (hotfix)

Summary

Hotfix for v0.43.0. The ShapERuntime introduced in v0.43.0 was broken on every real invocation: the code accessed result.meshes[0] and .vertices, but the actual diffusers ShapEPipeline returns .images[0] with .verts (and requires output_type="mesh" to produce a mesh at all). Unit tests passed because the mocks were written to match the incorrect mental model rather than the real diffusers API. Caught by post-release code review before any GPU user could verify.

Fixes

• Pipeline now called with output_type="mesh".
• result.images[0] (not result.meshes[0]).
• mesh_data.verts.cpu().numpy() (not .vertices).
• Mocks rewritten to match the real diffusers API.

Cleanup (co-located with the fix)

• Removed frame_size constructor kwarg. It is silently ignored when output_type="mesh"; exposing it was misleading.
• Parametrized the three test_raises_when_* missing-deps tests (DRY).
• Hoisted module-level imports out of test bodies.
• Removed stale "v0.43.0" version string from the NotImplementedError message.

Migration

None. The runtime is internal to the 3d/generation modality. Anyone who pulled shap-e between v0.43.0 release and this hotfix would have hit the AttributeError on first probe; rerun muse models probe shap-e after this release.

Tests

Full fast lane: 11 ShapERuntime tests passing (3 missing-deps tests collapsed to 1 parametrized × 3 cases). Full 3D suite: 125 passing. Meta-test: 148 passing.