Single-object viewer POC (#14)

This commit implements a Sketchfab-style single-object viewer as a minimal
proof-of-concept.

### `@storyteller/studio-web`
This is a new package to house web components for interfacing with the
`@storyteller/studio` WASM library. It currently includes a single component,
`<sts-viewer />`, which is exported from `@storyteller/studio-web/viewer`.

### `react-frontend`
This is a new application intended as a proof-of-concept and testbed for React
interop with `@storyteller/studio-web`.

Web components are currently a little bit fiddly to use in a React application.
`react-frontend/src/app/studio-viewer.tsx` demonstrates how a React-idiomatic
component can be written as a thin wrapper around a web component, and
`react-frontend/src/app/app.tsx` demonstrates that wrapper component in use.

studio-web/vite.config.ts

@@ -0,0 +1,50 @@
+/// <reference types='vitest' />
+import { defineConfig } from "vite";
+import dts from "vite-plugin-dts";
+import * as path from "path";
+import { nxViteTsPaths } from "@nx/vite/plugins/nx-tsconfig-paths.plugin";
+
+export default defineConfig({
+  cacheDir: "../node_modules/.vite/studio-web",
+
+  plugins: [
+    nxViteTsPaths(),
+    dts({
+      entryRoot: "src",
+      tsConfigFilePath: path.join(__dirname, "tsconfig.lib.json"),
+      skipDiagnostics: true,
+    }),
+  ],
+
+  // Uncomment this if you are using workers.
+  // worker: {
+  //  plugins: [ nxViteTsPaths() ],
+  // },
+
+  // Configuration for building your library.
+  // See: https://vitejs.dev/guide/build.html#library-mode
+  build: {
+    lib: {
+      // Could also be a dictionary or array of multiple entry points.
+      entry: "src/index.ts",
+      name: "studio-web",
+      fileName: "index",
+      // Change this to the formats you want to support.
+      // Don't forget to update your package.json as well.
+      formats: ["es", "cjs"],
+    },
+    rollupOptions: {
+      // External packages that should not be bundled into your library.
+      external: [],
+    },
+  },
+
+  test: {
+    globals: true,
+    cache: {
+      dir: "../node_modules/.vitest",
+    },
+    environment: "jsdom",
+    include: ["src/**/*.{test,spec}.{js,mjs,cjs,ts,mts,cts,jsx,tsx}"],
+  },
+});