Part.Clone() re-clones from the drawing's unrotated program, re-rotates,
and walks all CNC codes twice for bounding box — 4 O(c) passes per clone.
CloneAtOffset clones from the already-rotated program and computes the
bounding box arithmetically, reducing to 1 O(c) pass per clone.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>