Add a booleanShapePath engine that runs union/subtract/intersect/
exclude/flatten through paper.js and returns normalized result path
data plus per-operand stroke segments, so boolean results are real
vector paths instead of SVG mask approximations.
- Store the computed pathData on boolean groups and recompute it when
the operation changes; flatten legacy groups into ordinary path nodes
- Render previews and SVG/PSD exports from the computed result path,
keeping each operand's stroke style on the boundary it contributes
- Open boolean results in the path editor and flatten them on commit
- Add paper 0.12.18 with a paper-core type shim and mark it as a
server-external package for the standalone Next build
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
