@@ -0,0 +1,10 @@
+---
+'@object-ui/i18n': patch
+---
+
+feat(i18n): the Studio inspectors' page block, action, dataset, flow node, app navigation and dashboard widget strings move into the `studio` namespace
+
+Clause-②: no
+Metadata-protocol: none
+
+- **Second slice of the move ruled on objectstack#25922** (6431032267, Q2 = A; kept by 6431234244). The 520 keys under `engine.inspector.pageBlock.*`, `engine.inspector.action.*`, `engine.inspector.dataset.*`, `engine.inspector.flowNode.*`, `engine.inspector.appNav.*` and `engine.inspector.widget.*` now live in `@object-ui/i18n/namespaces/studio` instead of `@object-ui/app-shell`'s private table, text unchanged in both `en` and `zh`. Studio reads the same strings; a Chinese viewer sees these labels in English for the moment the `zh` catalogue takes to load, as with the first slice. No export changes.
@@ -31,6 +31,11 @@ vi.mock('../previews/useDatasetCatalog', () => ({
 }));
 
 import { DashboardWidgetInspector } from './DashboardWidgetInspector';
+// The inspector's `engine.inspector.*` rows live in `@object-ui/i18n`'s `studio`
+// namespace, whose `zh` catalogue is fetched on demand (objectstack#25922).
+// Resident before any case, so the zh rows below read synchronously.
+import { loadStudioCatalogue } from '@object-ui/i18n/namespaces/studio';
+await loadStudioCatalogue('zh');
 
 afterEach(cleanup);
 
 
@@ -80,6 +80,11 @@ import { registerDefaultMetadataSchemas } from '../default-schemas';
 import { registerBuiltinPreviews } from '../previews';
 import { registerBuiltinInspectors } from '.';
 import { DatasetDefaultInspector, objectChangePatch } from './DatasetDefaultInspector';
+// The inspector's `engine.inspector.*` rows live in `@object-ui/i18n`'s `studio`
+// namespace, whose `zh` catalogue is fetched on demand (objectstack#25922).
+// Resident before any case, so the zh rows below read synchronously.
+import { loadStudioCatalogue } from '@object-ui/i18n/namespaces/studio';
+await loadStudioCatalogue('zh');
 
 const DATASET_JSON_SCHEMA = z.toJSONSchema(getMetadataTypeSchema('dataset') as z.ZodType, {
   io: 'input',
 
@@ -31,6 +31,11 @@ import { FlowNodeInspector } from './FlowNodeInspector';
 import { encodeNestedNodeId } from './flow-nested-selection';
 import { t, tFormat, type SupportedLocale } from '../i18n';
 import type { MetadataSelection } from '../preview-registry';
+// The inspector's `engine.inspector.*` rows live in `@object-ui/i18n`'s `studio`
+// namespace, whose `zh` catalogue is fetched on demand (objectstack#25922).
+// Resident before any case, so the zh rows below read synchronously.
+import { loadStudioCatalogue } from '@object-ui/i18n/namespaces/studio';
+await loadStudioCatalogue('zh');
 
 afterEach(cleanup);
 
 
@@ -45,6 +45,11 @@ const state = vi.hoisted(() => ({
 vi.mock('../useMetadata', () => ({ useMetadataClient: () => state.metadataClient }));
 
 import { PageBlockInspector } from './PageBlockInspector';
+// The inspector's `engine.inspector.*` rows live in `@object-ui/i18n`'s `studio`
+// namespace, whose `zh` catalogue is fetched on demand (objectstack#25922).
+// Resident before any case, so the zh rows below read synchronously.
+import { loadStudioCatalogue } from '@object-ui/i18n/namespaces/studio';
+await loadStudioCatalogue('zh');
 
 afterEach(cleanup);
 
 
@@ -48,6 +48,11 @@ vi.mock('../useMetadata', () => ({
 }));
 
 import { PageBlockInspector } from './PageBlockInspector';
+// The inspector's `engine.inspector.*` rows live in `@object-ui/i18n`'s `studio`
+// namespace, whose `zh` catalogue is fetched on demand (objectstack#25922).
+// Resident before any case, so the zh rows below read synchronously.
+import { loadStudioCatalogue } from '@object-ui/i18n/namespaces/studio';
+await loadStudioCatalogue('zh');
 
 afterEach(cleanup);
 
 
@@ -41,6 +41,11 @@ vi.mock('../useMetadata', () => ({
 }));
 
 import { PageBlockInspector } from './PageBlockInspector';
+// The inspector's `engine.inspector.*` rows live in `@object-ui/i18n`'s `studio`
+// namespace, whose `zh` catalogue is fetched on demand (objectstack#25922).
+// Resident before any case, so the zh rows below read synchronously.
+import { loadStudioCatalogue } from '@object-ui/i18n/namespaces/studio';
+await loadStudioCatalogue('zh');
 
 afterEach(cleanup);
 
 
@@ -34,6 +34,11 @@ import { SchemaRenderer, PredicateScopeProvider } from '@object-ui/react';
 import { PageBlockInspector } from './PageBlockInspector';
 import type { MetadataInspectorProps } from '../inspector-registry';
 import type { SupportedLocale } from '../i18n';
+// The inspector's `engine.inspector.*` rows live in `@object-ui/i18n`'s `studio`
+// namespace, whose `zh` catalogue is fetched on demand (objectstack#25922).
+// Resident before any case, so the zh rows below read synchronously.
+import { loadStudioCatalogue } from '@object-ui/i18n/namespaces/studio';
+await loadStudioCatalogue('zh');
 
 afterEach(cleanup);
 
 
@@ -0,0 +1,62 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * objectstack#25922 slice S2 — the page block, action, dataset, flow node, app
+ * navigation and dashboard widget inspector rows (`engine.inspector.{pageBlock,
+ * action,dataset,flowNode,appNav,widget}.*`) live in `@object-ui/i18n`'s
+ * `studio` namespace, and app-shell's `t()` still answers every one of them the
+ * way it did when they sat in its own table.
+ *
+ * What would break it:
+ *   - a row copied back into the app-shell table with a different value — the
+ *     table is asked first, so it would shadow the namespace silently;
+ *   - the namespace fallback dropped from `lookupString` — every moved key
+ *     would echo back as itself;
+ *   - a family emptied out of the namespace, which every per-key assertion
+ *     below would then pass over nothing. The floors are per FAMILY, by name,
+ *     so one family draining cannot hide behind another one growing.
+ *
+ * The oracle is the namespace's own catalogues, read through
+ * `loadStudioCatalogue` (the module's public door), not a copy of their text.
+ */
+import { describe, expect, it } from 'vitest';
+import { loadStudioCatalogue } from '@object-ui/i18n/namespaces/studio';
+import { t } from '../i18n';
+
+const EN = await loadStudioCatalogue('en');
+// Resident before any case, so the zh lookups below read synchronously.
+const ZH = await loadStudioCatalogue('zh');
+
+/** Family → the fewest keys it may carry (measured at the move, rounded down). */
+const S2_FAMILY_FLOOR: Readonly<Record<string, number>> = Object.freeze({
+  pageBlock: 160,
+  action: 120,
+  dataset: 80,
+  flowNode: 40,
+  appNav: 40,
+  widget: 40,
+});
+
+const familyKeys = (family: string): string[] =>
+  Object.keys(EN).filter((key) => key.startsWith(`engine.inspector.${family}.`));
+
+describe('S2 inspector rows answer from the studio namespace (objectstack#25922)', () => {
+  it.each(Object.entries(S2_FAMILY_FLOOR))('%s: the namespace carries the family, in en and zh', (family, floor) => {
+    const keys = familyKeys(family);
+    expect(keys.length).toBeGreaterThanOrEqual(floor);
+    expect(keys.filter((key) => !(key in ZH))).toEqual([]);
+  });
+
+  it.each(Object.keys(S2_FAMILY_FLOOR))('%s: t() answers every key with the namespace value', (family) => {
+    const wrong = familyKeys(family).flatMap((key) => {
+      const out: string[] = [];
+      if (t(key, 'en-US') !== EN[key]) out.push(`en-US ${key}: ${t(key, 'en-US')}`);
+      if (t(key, 'zh-CN') !== ZH[key]) out.push(`zh-CN ${key}: ${t(key, 'zh-CN')}`);
+      // A language the namespace has no catalogue for reads English, as it did
+      // from the app-shell table.
+      if (t(key, 'de-DE') !== EN[key]) out.push(`de-DE ${key}: ${t(key, 'de-DE')}`);
+      return out;
+    });
+    expect(wrong).toEqual([]);
+  });
+});