* refactor(design-jsx): extract design JSX into its own package
Design JSX elements, helpers, schema, reference, and JSX export only need
the scene graph, yet lived in Core, so every consumer of the authoring API
pulled in the renderer, layout, and file formats.
@open-pencil/design-jsx now owns them and depends only on scene-graph. The
renderer takes icon lookup, SVG conversion, vector creation, and layout as
DesignJSXServices; Core binds its own and exports the bound renderJSX and
renderTree from @open-pencil/core/design-jsx.
* feat(design-jsx): export the JSX runtime for TSX authoring
The package already had a JSX runtime, but nothing exported it, so design
trees could only be written as function calls or JSX strings. Export
`./jsx-runtime` and `./jsx-dev-runtime` so `jsxImportSource` works, and make
`Fragment` produce the same empty-type node as `<>` in `renderJSX` strings.
* fix(design-jsx): render fragments nested in other elements
A fragment builds a node with an empty type, which only renderJSX expanded, and only at the root. Nested fragments and fragments passed to renderTree failed with 'Unknown element: <>'. Inline fragment children when trees are built, and share root expansion between renderTree and renderJSX.
- Configure oxfmt custom import groups for workspace, app, package, and test aliases
- Keep type imports grouped with their matching source category instead of one global tail group
- Expand the format script to cover formatter config, Vite files, and scripts
- Merge structural lint rules into oxlint.json and remove the second config file
- Add #tests/* path aliases and rewrite deep test helper imports
- Ban new deep parent-relative imports through the shared lint config
- Move render.test.ts into focused JSX builder, tree render, grid layout, and text prop files
- Preserve all 56 render tests and keep scoped non-null assertion enforcement on the new folder
- Validate the split with the render/jsx test folder and the full check command
