Convert Weldment to Assembly

The cleanest general path in this recovered conversation is Save Bodies: prepare and rebuild the master part, update the cut list, confirm separate solid bodies, name the outputs, and create the assembly from the same workflow. The resulting parts normally retain the original coordinate relationship, which is useful for rigid fabricated frames. Moving components still need real assembly mates, and every generated file should be checked for transferred properties, naming, references, and BOM behavior.