- Replace clipboard, variable, centerline, layout, menu, and text formatting assertions with explicit guards
- Use expectDefined and getNodeOrThrow instead of postfix non-null assertions
- Validate affected engine and E2E tests
- 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 layout.test.ts into auto-layout and grid-layout files
- Add shared layout helpers for test graph setup and fixture loading
- Preserve all 95 layout tests after the split
