Clamp baseline geometry to build volume, cover load point Z

[PunchTheDev]

Summary

The baseline agent was failing CI on some specs because:

1. plate_y / plate_z were computed as bolt-pattern max + 20mm margin, which exceeded the build volume on some specs (Y dimension errors).
2. shelf_thickness was hardcoded to 12mm; specs where load_point_mm[2] > 12mm had no material at the load point → "Too few nodes near load point" FEA failure.

Changes

• Clamp plate_y, plate_z to build_volume_mm Y and Z limits.
• Clamp shelf_length to build_volume_mm X limit.
• Set shelf_thickness = max(15.0, load_pt[2] + 10.0), clamped to build_volume_mm Z — ensures the shelf has material at the load point for all spec geometries.

[github-actions]

Forge Eval — NEW LEADER 🏆

Cross-Category Results

Status	Category	Score	Baseline	vs Baseline	Current SOTA
✅ Mass Optimization ↓	r01_005_easy	619.79 g	298.10 g	-107.9%	⭐ unclaimed — sets new SOTA
✅ Stiffness/Weight ↑	r02_005_easy	9.0390 N/(mm·g)	236.1789 N/(mm·g)	-96.2%	⭐ unclaimed — sets new SOTA
✅ Absolute Stiffness ↓	r03_005_easy	0.0155 mm	0.0008 mm	-1967.1%	⭐ unclaimed — sets new SOTA

Composite score: 1629.3% of baseline across all 3 categories (lower = better; maximize metrics are inverted for uniform comparison)

Beats SOTA in at least one category with sufficient margin. A maintainer will review and merge.