chore: scaffold Vite + React 19 + Tailwind v4 app on HMDesign

Start the React rebuild of the DWG/DXF viewer (#1).

- HMDesign is a git submodule (vendor/HMDesign, main) and its
  packages/ui is an npm workspace, so @hm-design/ui resolves to the
  submodule and shares this repo's node_modules.
- scripts/setup-hmdesign.mjs (postinstall) builds the package dist and
  points vendor/HMDesign/node_modules at ours with a junction, because
  HMDesign's build script reads typescript/shadcn from its own root.
  Nothing inside the submodule is modified.
- Versions follow HMDesign (react 19.3.0, vite 8.3.0, tailwindcss
  4.3.3, typescript 7.0.2) and the sample (three 0.185.1, dxf-parser
  1.1.2, opentype.js 2.0.0).
- CSS entry: tailwindcss + @hm-design/ui/tailwind.css (index.css).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

vite.config.ts

@@ -0,0 +1,22 @@
+import { defineConfig } from "vite"
+import react from "@vitejs/plugin-react"
+import tailwindcss from "@tailwindcss/vite"
+
+export default defineConfig({
+  plugins: [react(), tailwindcss()],
+  server: {
+    port: 5173,
+    strictPort: true,
+  },
+  resolve: {
+    // @hm-design/ui is a linked workspace (vendor/HMDesign/packages/ui); keep one React instance.
+    dedupe: ["react", "react-dom"],
+  },
+  optimizeDeps: {
+    // Only crawl this app's entry; vendor/HMDesign carries its own HTML entries (Storybook exports).
+    entries: ["index.html"],
+    include: ["three", "dxf-parser", "opentype.js"],
+  },
+  // acadrust-dwg WASM is imported with `?url` (src/engine/viewer2d/acadrustParser.ts).
+  assetsInclude: ["**/*.wasm"],
+})