Add panorama previews and repair beta export rendering

shared/draft-selection.ts

@@ -0,0 +1,16 @@
+import { datasetSchema, type DatasetManifest } from "./protocol";
+
+export function selectDraftLocations(manifest: DatasetManifest, ids: string[]) {
+  const available = manifest.availableViewpoints ?? manifest.viewpoints;
+  const selected = new Set(ids);
+  if (
+    selected.size !== ids.length ||
+    ids.some((id) => !available.some((p) => p.id === id))
+  )
+    throw new Error("Choose unique locations from this capture");
+  return datasetSchema.parse({
+    ...manifest,
+    availableViewpoints: available,
+    viewpoints: available.filter((p) => selected.has(p.id)),
+  });
+}