Complete worked reference compositions with full SVG or cross-references #32
Description
Priority: P3 | Source: PR #21 self-review (F8)
Problem
The "Worked Reference: Car Drivetrain Composition" section in mechanical-illustration-skill.txt (lines 516-544) provides a planning outline and SVG structure but no actual SVG code. Meanwhile the shape library has the full SVG sedan. This gap makes the "reference composition" less useful than the raw shape library entry.
Suggested Fix
Either include the full SVG for the car drivetrain composition, or explicitly cross-reference the shape library: "Use the Sedan Side Profile from svg-shape-library.txt as the starting shape."