design-sync package shape: cssEntry local @imports silently drop tokens

When syncing a React design system via the design-sync package shape, the converter ships your cssEntry as _ds_bundle.css but does NOT follow relative @import "./tokens/..." — so tokens.css/fonts.css never reach the bundle. Symptoms: [CSS_IMPORT_MISSING], [TOKENS_MISSING] (var(--x) undefined), and downstream [RENDER_THIN] because components render unstyled (a symptom, not a preview bug). Fix: make cssEntry fully self-contained by concatenating fonts + tokens + component CSS into one styles.css at build time. Two more gotchas: guidelinesGlob is markdown-only (copy reference images into ds-bundle/guidelines/.../assets in a post-build step since the build wipes ds-bundle each run), and you can regroup components with a category-only stub .md via docsMap while keeping the synthesized prompt.md body.