feat(web): render bgm setups as a 3D table

Wire the tabletop library into the setup detail route: seed the store
from the setup, resolve the surface mount tree, and render world and HUD
surfaces. Add serializedToPackage to convert the vite-emitted package.

packages/tabletop/src/index.ts

@@ -11,6 +11,9 @@ export {
 } from './part.js';
 export { resolveAssetUrl, assetUrl, traceImage } from './http.js';
 
+// Serialized package -> Package conversion.
+export { serializedToPackage } from './package.js';
+
 // State store + derived render state.
 export {
   useTabletopStore,