diff --git a/src/workspaces/officerdev/src/AppRegistry/AppRegistry.test.ts b/src/workspaces/officerdev/src/AppRegistry/AppRegistry.test.ts
new file mode 100644
index 00000000..1b440a79
--- /dev/null
+++ b/src/workspaces/officerdev/src/AppRegistry/AppRegistry.test.ts
@@ -0,0 +1,39 @@
+import { describe, expect, test } from 'bun:test';
+import { apps } from './AppRegistry';
+import { findDuplicateKeys, metasToRegistry } from './useAppRegistry';
+
+/**
+ * `metasToRegistry` is `Object.fromEntries`, so two metas sharing a key means one app silently stops
+ * existing — and every panel already storing that `appType` renders the survivor instead. Nothing at
+ * runtime can recover from that, so it is caught here, over the real list the app actually mounts.
+ */
+describe('the real app registry', () => {
+  test('every app key is unique', () => {
+    expect(findDuplicateKeys(apps)).toEqual([]);
+  });
+
+  test('no app is lost between the meta list and the registry', () => {
+    expect(Object.keys(metasToRegistry(apps)).length).toBe(apps.length);
+  });
+
+  test('every app has a key, a name and a component', () => {
+    const incomplete = apps.filter((a) => !a.key || !a.name || !a.component).map((a) => a.key ?? '(no key)');
+    expect(incomplete).toEqual([]);
+  });
+});
+
+describe('findDuplicateKeys', () => {
+  const meta = (key: string) => ({ key }) as (typeof apps)[number];
+
+  test('reports nothing for a clean list', () => {
+    expect(findDuplicateKeys([meta('a'), meta('b')])).toEqual([]);
+  });
+
+  test('reports a repeated key once, however many times it repeats', () => {
+    expect(findDuplicateKeys([meta('a'), meta('a'), meta('a')])).toEqual(['a']);
+  });
+
+  test('reports each distinct collision', () => {
+    expect(findDuplicateKeys([meta('a'), meta('b'), meta('a'), meta('b')])).toEqual(['a', 'b']);
+  });
+});
diff --git a/src/workspaces/officerdev/src/AppRegistry/AppRegistry.tsx b/src/workspaces/officerdev/src/AppRegistry/AppRegistry.tsx
index 6623059e..613704c2 100644
--- a/src/workspaces/officerdev/src/AppRegistry/AppRegistry.tsx
+++ b/src/workspaces/officerdev/src/AppRegistry/AppRegistry.tsx
@@ -21,7 +21,7 @@ import { appRegistryMetas as qrTransferMetas } from '../apps/QrTransfer';
 import { appRegistryMetas as davMetas } from '../apps/Dav';
 import { useAppRegistry } from './useAppRegistry';
 
-const apps = [
+export const apps = [
   ...fileBrowserMetas,
   ...terminalMetas,
   ...codeEditorMetas,
diff --git a/src/workspaces/officerdev/src/AppRegistry/useAppRegistry/index.ts b/src/workspaces/officerdev/src/AppRegistry/useAppRegistry/index.ts
index f5cbe731..0ca19d08 100644
--- a/src/workspaces/officerdev/src/AppRegistry/useAppRegistry/index.ts
+++ b/src/workspaces/officerdev/src/AppRegistry/useAppRegistry/index.ts
@@ -1 +1,7 @@
-export { useAppRegistry, type UseAppRegistryType, type AppRegistryMeta } from './useAppRegistry';
+export {
+  useAppRegistry,
+  metasToRegistry,
+  findDuplicateKeys,
+  type UseAppRegistryType,
+  type AppRegistryMeta,
+} from './useAppRegistry';
diff --git a/src/workspaces/officerdev/src/AppRegistry/useAppRegistry/useAppRegistry.ts b/src/workspaces/officerdev/src/AppRegistry/useAppRegistry/useAppRegistry.ts
index 070e7888..eae13efa 100644
--- a/src/workspaces/officerdev/src/AppRegistry/useAppRegistry/useAppRegistry.ts
+++ b/src/workspaces/officerdev/src/AppRegistry/useAppRegistry/useAppRegistry.ts
@@ -15,5 +15,20 @@ export function useAppRegistry(initialApps: AppRegistryMeta[] = []) {
 
 export type UseAppRegistryType = ReturnType<typeof useAppRegistry>;
 
-const metasToRegistry = (metas: AppRegistryMeta[]): AppRegistryMap =>
-  Object.fromEntries(metas.map(({ key, ...entry }) => [key, entry]));
+export const findDuplicateKeys = (metas: AppRegistryMeta[]): string[] => [
+  ...new Set(metas.map((m) => m.key).filter((key, i, keys) => keys.indexOf(key) !== i)),
+];
+
+/**
+ * A collision here last-wins silently: one app stops existing, and every panel already holding its
+ * `appType` renders the other app's component instead. It is an authoring mistake, so it is caught by a
+ * test over the real meta list (`AppRegistry.test.ts`) rather than by throwing — a duplicate key is not a
+ * reason to take the owner's dashboard down at runtime.
+ */
+export const metasToRegistry = (metas: AppRegistryMeta[]): AppRegistryMap => {
+  const duplicates = findDuplicateKeys(metas);
+  if (duplicates.length > 0)
+    console.error(`AppRegistry: duplicate app key(s) ${duplicates.join(', ')} — one app is unreachable`);
+
+  return Object.fromEntries(metas.map(({ key, ...entry }) => [key, entry]));
+};
diff --git a/src/workspaces/officerdev/src/apps/Dashboards/DashboardPreview.tsx b/src/workspaces/officerdev/src/apps/Dashboards/DashboardPreview.tsx
index 7e4d9d96..af639137 100644
--- a/src/workspaces/officerdev/src/apps/Dashboards/DashboardPreview.tsx
+++ b/src/workspaces/officerdev/src/apps/Dashboards/DashboardPreview.tsx
@@ -6,7 +6,7 @@ import { useGlobal } from 'hooks/useGlobal';
 import { useClient } from 'hooks/useClient';
 import { useUserState } from 'state/useUserState';
 import { useDashboardState, persistDashboardState } from 'state/useDashboardState';
-import { WorkspaceLayout, WorkspaceView, createDefaultLayout } from '../../components/Workspace';
+import { WorkspaceLayout, WorkspaceView, createDefaultLayout, uid } from '../../components/Workspace';
 import type { LayoutNode, DashboardDefinition } from '../../components/Workspace';
 import { Button } from '@/components/ui/button';
 import { generateSlug, slugify } from 'helpers/slug';
@@ -22,9 +22,6 @@ import {
 
 // --- Layout Templates ---
 
-let tplCounter = 0;
-const tplUid = () => `tpl-${++tplCounter}`;
-
 type LayoutTemplate = {
   name: string;
   layout: () => LayoutNode;
@@ -33,17 +30,17 @@ type LayoutTemplate = {
 const templates: LayoutTemplate[] = [
   {
     name: 'Single',
-    layout: () => ({ type: 'panel', id: tplUid(), appType: null }),
+    layout: () => ({ type: 'panel', id: uid(), appType: null }),
   },
   {
     name: '2 Columns',
     layout: () => ({
       type: 'group',
-      id: tplUid(),
+      id: uid(),
       direction: 'horizontal',
       children: [
-        { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
-        { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
+        { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
+        { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
       ],
     }),
   },
@@ -51,18 +48,18 @@ const templates: LayoutTemplate[] = [
     name: 'Main + Side',
     layout: () => ({
       type: 'group',
-      id: tplUid(),
+      id: uid(),
       direction: 'horizontal',
       children: [
-        { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
+        { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
         {
           node: {
             type: 'group',
-            id: tplUid(),
+            id: uid(),
             direction: 'vertical',
             children: [
-              { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
-              { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
+              { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
+              { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
             ],
           },
           size: 50,
@@ -74,11 +71,11 @@ const templates: LayoutTemplate[] = [
     name: 'Sidebar',
     layout: () => ({
       type: 'group',
-      id: tplUid(),
+      id: uid(),
       direction: 'horizontal',
       children: [
-        { node: { type: 'panel', id: tplUid(), appType: null }, size: 25 },
-        { node: { type: 'panel', id: tplUid(), appType: null }, size: 75 },
+        { node: { type: 'panel', id: uid(), appType: null }, size: 25 },
+        { node: { type: 'panel', id: uid(), appType: null }, size: 75 },
       ],
     }),
   },
@@ -86,17 +83,17 @@ const templates: LayoutTemplate[] = [
     name: '2x2 Grid',
     layout: () => ({
       type: 'group',
-      id: tplUid(),
+      id: uid(),
       direction: 'vertical',
       children: [
         {
           node: {
             type: 'group',
-            id: tplUid(),
+            id: uid(),
             direction: 'horizontal',
             children: [
-              { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
-              { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
+              { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
+              { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
             ],
           },
           size: 50,
@@ -104,11 +101,11 @@ const templates: LayoutTemplate[] = [
         {
           node: {
             type: 'group',
-            id: tplUid(),
+            id: uid(),
             direction: 'horizontal',
             children: [
-              { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
-              { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
+              { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
+              { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
             ],
           },
           size: 50,
@@ -120,22 +117,22 @@ const templates: LayoutTemplate[] = [
     name: 'Cols + Bottom',
     layout: () => ({
       type: 'group',
-      id: tplUid(),
+      id: uid(),
       direction: 'vertical',
       children: [
         {
           node: {
             type: 'group',
-            id: tplUid(),
+            id: uid(),
             direction: 'horizontal',
             children: [
-              { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
-              { node: { type: 'panel', id: tplUid(), appType: null }, size: 50 },
+              { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
+              { node: { type: 'panel', id: uid(), appType: null }, size: 50 },
             ],
           },
           size: 70,
         },
-        { node: { type: 'panel', id: tplUid(), appType: null }, size: 30 },
+        { node: { type: 'panel', id: uid(), appType: null }, size: 30 },
       ],
     }),
   },
diff --git a/src/workspaces/officerdev/src/components/Workspace/index.ts b/src/workspaces/officerdev/src/components/Workspace/index.ts
index 2693b69c..bf3bf49e 100644
--- a/src/workspaces/officerdev/src/components/Workspace/index.ts
+++ b/src/workspaces/officerdev/src/components/Workspace/index.ts
@@ -14,6 +14,7 @@ export type {
 } from './types';
 export type { DropPosition } from './layout-utils';
 export {
+  uid,
   createDefaultLayout,
   splitPanel,
   removePanel,
diff --git a/src/workspaces/officerdev/src/components/Workspace/layout-utils.ts b/src/workspaces/officerdev/src/components/Workspace/layout-utils.ts
index 4fcfe517..d8419413 100644
--- a/src/workspaces/officerdev/src/components/Workspace/layout-utils.ts
+++ b/src/workspaces/officerdev/src/components/Workspace/layout-utils.ts
@@ -1,7 +1,8 @@
 import type { LayoutNode, LayoutPanel, LayoutGroup, PanelConfig } from './types';
 
 let counter = 0;
-const uid = () => `p-${Date.now()}-${++counter}`;
+/** The only way to mint a panel id. Time-stamped, so ids stay unique across page loads and dashboards. */
+export const uid = () => `p-${Date.now()}-${++counter}`;
 
 export const createDefaultLayout = (): LayoutPanel => ({
   type: 'panel',
diff --git a/src/workspaces/officerdev/src/useAppRegistry.ts b/src/workspaces/officerdev/src/useAppRegistry.ts
deleted file mode 100644
index cb46d942..00000000
--- a/src/workspaces/officerdev/src/useAppRegistry.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-import type { AppRegistryMap } from './components/Workspace';
-
-export function useAppRegistry(): AppRegistryMap {
-  return {};
-}
diff --git a/test-setup.ts b/test-setup.ts
index fc3b58e6..7fb6068e 100644
--- a/test-setup.ts
+++ b/test-setup.ts
@@ -9,6 +9,9 @@ Object.assign(globalThis, {
   navigator: window.navigator,
   location: window.location,
   history: window.history,
+  // Several modules read storage at import time, so this must exist before the first import, not first render.
+  localStorage: window.localStorage,
+  sessionStorage: window.sessionStorage,
   HTMLElement: window.HTMLElement,
   Element: window.Element,
   Node: window.Node,