Summary

• STEP format requires each solid to have its own closed, watertight boundary
• Previously all component triangles were merged into one ClosedShell/ManifoldSolidBrep, violating STEP constraints
• Now each component box is processed individually with its own solid and proper naming
• Fixed board mesh being incorrectly processed as a component

Test Results

• basics04: 3 solids (board + R1 + C1) - previously was 2 merged solids
• repro01: 5 solids - previously was 2 merged solids
• All 10 existing tests pass
• OCCT validation passes for all test cases

Test plan

• All existing tests pass
• Verified solid count increased in component tests
• STEP files validate with occt-import-js
• Updated repro01 snapshot shows component blocks

/claim #6

Fixes #6