Add parametric LBSBB8-3030 gusseted corner bracket

[a1423150775-dotcom]

Summary

• Added a new independent parametric gusseted_corner_bracket family.
• Used the LBSBB8-3030 specification row as the documented baseline.
• Built the two elongated through-slots in the local coordinate system of each wing, with independent work planes and cut directions.
• Kept the triangular gusset fused into the same solid as the two perpendicular wings.
• Performed staged geometric checks and validation on the family.

Validation

• uv run bench2 validate gusseted_corner_bracket --seeds 3
• Rendered the default, orthographic, and comparison images in designs/gusseted_corner_bracket/

Notes

This PR is for demonstration only and remains Draft. It should not be merged.

[github-actions]

Welcome, and thanks for the family PR! Three things that answer most questions:

• No checks running? A maintainer must click Approve workflows once for your first PR — pending, not ignored.
• Red gate? The message tells you the fix: click Details, or read the bench2 validate report comment posted after each run. Reproduce locally with uv sync && uv run bench2 validate <family> (debug help).
• Scope: designs/<family>/ holds only the package files (reference drawings/photos go in the family issue), and the PR checklist must be fully ticked. Not done yet? Mark the PR as a Draft.

[github-actions]

bench2 validate

gusseted_corner_bracket

  ✓ family.json: keys + base_plane valid
  ✓ pieces: build(13 params) + PARAM_SPEC + check present
  ✓ PARAM_SPEC: 13 params, all entries complete
  ✓ easy: 4/4 seeds sample+check+build+execute clean
  ✓ medium: 4/4 seeds sample+check+build+execute clean
  ✓ hard: 4/4 seeds sample+check+build+execute clean
  ✓ difficulty separation: difficulties produce distinct programs
  ✓ geometry novelty: 12/12 unique shapes (0% duplicate)
  ✓ solids: every instance non-degenerate, 1 solid(s) each
PASS — designs/gusseted_corner_bracket

Previews: the previews artifact on this run.