Implementation

Extend override validation and native marking generation for explicit double-yellow centre lines and per-side edge-line styles.
Extend the Chinese Workbench selection/form flow without adding another editor or output format.
Add compiler and Workbench regression coverage for valid and invalid payloads, generated geometry, and layer adapter completeness.
Compile/check Nantaizi, run native/Workbench/build-stage/Blender tests, then run the native Blender/Cesium/preview chain.