v0.3.51

What's Changed

• test: cover #268 untested acceptance criteria + draftwright allowlist by @pzfreo in #274
• fix: sync uv.lock build123d-mcp version to 0.3.51.dev0 by @pzfreo in #275
• feat: pre-export validity gate (validate tool + export warning) by @pzfreo in #276
• fix: base validity gate on edge-face map, not build123d.is_manifold by @pzfreo in #277
• feat: catch mesh-level non-manifold defects in the validity gate by @pzfreo in #278

Full Changelog: v0.3.50...v0.3.51