fix(adr-0047): verification-round fixes — switcher schema fallback, hollow-view hydration, getView type bug

- ListView reads showViewSwitcher from the schema too (ObjectView/
  InterfaceListPage stamp it there; the prop-only read left the switcher
  permanently hidden)
- InterfaceListPage: prefer source-view candidates that actually carry
  columns, and hydrate hollow ADR-0017 expansion items through
  listViewOverrides()/getView() — the same path ObjectView uses
- data-objectstack getView(): pass 'view' as the metadata type instead of
  the object name (hit /meta/<object>/<view> and always 404ed — latent
  since ADR-0017)

All verified live in the browser: data mode (tabs + dropdowns + Grid/
Kanban/Gallery/Calendar switcher, tab filter 10→2 records) and interface
mode (inherited columns, page-curated dropdowns only, locked grid,
closed toolbar, dropdown filter 10→2 records).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: os-zhuang

packages/app-shell/src/views/InterfaceListPage.tsx

@@ -35,14 +35,18 @@ interface InterfaceListPageProps {
  */
 function resolveSourceView(objectDef: any, sourceView?: string): any | undefined {
   const views: Record<string, any> = objectDef?.listViews || objectDef?.list_views || {};
-  if (sourceView) {
-    return (
-      views[`${objectDef.name}.${sourceView}`]
-      ?? views[sourceView]
-      ?? (sourceView === 'default' || sourceView === 'list' ? objectDef?.list : undefined)
-    );
-  }
-  return objectDef?.list ?? Object.values(views)[0];
+  // ADR-0017 expansion can serve a default-view item with an empty config
+  // while the full body lives on `objectDef.list` — prefer candidates that
+  // actually carry columns over hollow name matches.
+  const candidates = sourceView
+    ? [
+        views[`${objectDef?.name}.${sourceView}`],
+        views[sourceView],
+        ...(sourceView === 'default' || sourceView === 'list' ? [objectDef?.list] : []),
+      ]
+    : [objectDef?.list, ...Object.values(views)];
+  const present = candidates.filter(Boolean);
+  return present.find((v: any) => v?.columns) ?? present[0];
 }
 
 export function InterfaceListPage({ page, className }: InterfaceListPageProps) {
@@ -55,11 +59,45 @@ export function InterfaceListPage({ page, className }: InterfaceListPageProps) {
     () => (objects || []).find((o: any) => o.name === cfg.source),
     [objects, cfg.source],
   );
-  const viewDef = React.useMemo(
+  const resolvedView = React.useMemo(
     () => resolveSourceView(objectDef, cfg.sourceView),
     [objectDef, cfg.sourceView],
   );
 
+  // The view list endpoint can serve hollow expansion items (no columns);
+  // the full body lives behind the per-view overlay API — the same
+  // hydration ObjectView performs. Only fetch when the resolution came up
+  // hollow.
+  const [hydratedView, setHydratedView] = React.useState<any>(null);
+  React.useEffect(() => {
+    let cancelled = false;
+    setHydratedView(null);
+    if (!objectDef || !cfg.source || resolvedView?.columns) return;
+    const viewKey = resolvedView?.name
+      ?? (cfg.sourceView ? `${cfg.source}.${cfg.sourceView}` : undefined);
+    if (!viewKey) return;
+    (async () => {
+      try {
+        const ds: any = dataSource;
+        let full: any = null;
+        if (typeof ds?.listViewOverrides === 'function') {
+          const all = await ds.listViewOverrides(cfg.source);
+          full = all?.[viewKey] ?? null;
+        }
+        if (!full?.columns && typeof ds?.getView === 'function') {
+          full = await ds.getView(cfg.source, viewKey);
+        }
+        if (!cancelled && full && typeof full === 'object') setHydratedView(full);
+      } catch { /* hollow view stays hollow — renderer falls back to defaults */ }
+    })();
+    return () => { cancelled = true; };
+  }, [objectDef, cfg.source, cfg.sourceView, resolvedView, dataSource]);
+
+  const viewDef = React.useMemo(
+    () => (hydratedView ? { ...resolvedView, ...hydratedView } : resolvedView),
+    [resolvedView, hydratedView],
+  );
+
   const schema = React.useMemo(() => {
     if (!objectDef) return undefined;
     const view = viewDef || {};

packages/data-objectstack/src/index.ts

@@ -1379,8 +1379,10 @@ export class ObjectStackAdapter<T = unknown> implements DataSource<T> {
     try {
       const cacheKey = `view:${objectName}:${viewId}`;
       return await this.metadataCache.get(cacheKey, async () => {
-        // Try meta.getItem for view metadata
-        const result: any = await this.client.meta.getItem(objectName, viewId);
+        // Views are an independent metadata type (ADR-0017) — the first
+        // getItem argument is the metadata TYPE, not the object name.
+        // (Passing objectName here hit /meta/<object>/<view> and always 404ed.)
+        const result: any = await this.client.meta.getItem('view', viewId);
         if (result && result.item) return result.item;
         return result ?? null;
       });

packages/plugin-list/src/ListView.tsx

@@ -318,9 +318,13 @@ export const ListView = React.forwardRef<ListViewHandle, ListViewProps>(({
   onHiddenFieldsChange,
   onColumnStateChange,
   onRowClick,
-  showViewSwitcher = false,
+  showViewSwitcher: showViewSwitcherProp,
   ...props
 }, ref) => {
+  // The switcher can be enabled either by the host component (prop) or by
+  // the schema itself (ADR-0047 — ObjectView/InterfaceListPage stamp it on
+  // the schema when appearance.allowedVisualizations whitelists >1 type).
+  const showViewSwitcher = showViewSwitcherProp ?? (propSchema as any)?.showViewSwitcher ?? false;
   // i18n support for record count and other labels
   const { t } = useListViewTranslation();
   const { fieldLabel: resolveFieldLabel, actionLabel: resolveActionLabel } = useListFieldLabel();