@@ -0,0 +1,276 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * objectstack#28568 — the All metadata area's lists and directory mark a
+ * base's customizations (ADR-0146 D3, "On top, one surface"), from the
+ * server's customization read alone (`GET /api/v1/packages/:id/customizations`).
+ *
+ * The fixture is a read-only base, HotCRM (`hotcrm`), and its paired
+ * `hotcrm.custom` package carrying one overridden translation, one added email
+ * template and one extension field. The real pages and the real reader run;
+ * only `fetch` and the metadata client are stubbed. Pinned, each against a
+ * control:
+ *
+ *  - the translation list marks the served override "Customized (HotCRM)" and
+ *    the "only customizations" filter shows it alone;
+ *  - the email-template list holds the pair's item beside the base's, marked
+ *    "Added", and an override of ANOTHER member of a name marks no row;
+ *  - the directory's object tile counts the extension, and the header the base's total;
+ *  - a failed read draws no mark, no filter and no number, with the server's sentence;
+ *  - a base without a pair is unchanged, and Setup (no area) never reads;
+ *  - in the cross-package leg an item of a pair is labelled with its base.
+ */
+
+import '@testing-library/jest-dom/vitest';
+import * as React from 'react';
+import { describe, it, expect, vi, afterEach, beforeEach } from 'vitest';
+import { render, screen, cleanup, within, fireEvent } from '@testing-library/react';
+import { MemoryRouter } from 'react-router-dom';
+// The switch column waits on `audienceAnchorsOf`'s dynamic import of this exact
+// specifier (see `ResourceListPage.environmentScope-7611.test.tsx`).
+import '@objectstack/spec/identity';
+import { MetadataAreaHostContext, type MetadataAreaHost } from './metadataAreaHost';
+
+const BASE = 'hotcrm';
+const PAIR = 'hotcrm.custom';
+const PLAIN = 'com.example.crm';
+
+const LISTS: Record<string, Record<string, unknown>[]> = {
+  // A served override is served as the base's item, under the base's id.
+  translation: [
+    { name: 'crm_en', label: 'CRM English', _packageId: BASE },
+    { name: 'crm_de', label: 'CRM German', _packageId: BASE },
+    { name: 'plain_en', label: 'Plain English', _packageId: PLAIN },
+  ],
+  email_template: [
+    { name: 'welcome', label: 'Welcome', locale: 'en', _packageId: BASE },
+    { name: 'renewal_notice', label: 'Renewal notice', locale: 'en', _packageId: PAIR },
+  ],
+  permission: [
+    { name: 'crm_rep', label: 'CRM Rep', _packageId: BASE },
+    { name: 'crm_rep_plus', label: 'CRM Rep Plus', _packageId: PAIR },
+  ],
+};
+
+const CLIENT = {
+  list: async (type: string) =>
+    type === 'package' ? [{ manifest: { id: BASE, name: 'HotCRM', scope: 'installed' } }] : (LISTS[type] ?? []),
+};
+
+const entry = (type: string, domain: string) => ({
+  type,
+  label: type,
+  domain,
+  allowEnvironmentOverlay: true,
+  allowRuntimeCreate: true,
+});
+const ENTRIES = [
+  entry('object', 'data'),
+  entry('translation', 'ui'),
+  entry('email_template', 'system'),
+  entry('permission', 'security'),
+];
+
+vi.mock('./useMetadata', async (importOriginal) => ({
+  ...(await importOriginal<Record<string, unknown>>()),
+  useMetadataClient: () => CLIENT,
+  useMetadataTypes: () => ({ loading: false, error: null, entries: ENTRIES }),
+  useGlobalDiagnostics: () => ({
+    loading: false,
+    error: null,
+    summary: { entries: [], total: 0, scannedTypes: 0, scannedItems: 0 },
+    byType: {},
+    warnByType: {},
+    countsByType: { object: 3, translation: 2, email_template: 1 },
+    lockedByType: {},
+    packagesByType: Object.fromEntries(ENTRIES.map((e) => [e.type, [BASE, PLAIN]])),
+    allPackages: [BASE, PLAIN],
+    reload: () => {},
+  }),
+}));
+vi.mock('./i18n', async (importOriginal) => ({
+  ...(await importOriginal<Record<string, unknown>>()),
+  useMetadataLocale: () => 'en-US',
+}));
+vi.mock('../../hooks/useCanAuthorMetadata', async (importOriginal) => ({
+  ...(await importOriginal<Record<string, unknown>>()),
+  useCanAuthorMetadata: () => true,
+}));
+
+import { MetadataDirectoryPage } from './DirectoryPage';
+import { MetadataResourceListPage } from './ResourceListPage';
+import { registerDefaultMetadataSchemas } from './default-schemas';
+import { t, tFormat } from './i18n';
+
+registerDefaultMetadataSchemas();
+
+/** HotCRM's read: the overridden translation, an override of another member, the extension. */
+const HOTCRM_READ = {
+  packageId: BASE,
+  overrides: [
+    { type: 'email_template', name: 'welcome', member: 'zh-CN' },
+    { type: 'translation', name: 'crm_en', basedOn: '2.1.0' },
+  ],
+  extensions: [{ object: 'crm_account', kind: 'field', name: 'tier__c' }],
+  switchedOff: [],
+  counts: { overrides: 2, extensions: 1, switchedOff: 0 },
+};
+const EMPTY_READ = { packageId: PLAIN, overrides: [], extensions: [], switchedOff: [], counts: { overrides: 0, extensions: 0, switchedOff: 0 } };
+
+let customizationsFail = false;
+const fetchMock = vi.fn(async (url: string) => {
+  const json = (status: number, body: unknown) =>
+    new Response(JSON.stringify(body), { status, headers: { 'Content-Type': 'application/json' } });
+  const u = String(url);
+  if (u === '/api/v1/packages') {
+    return json(200, { success: true, data: { packages: [{ manifest: { id: BASE, name: 'HotCRM', scope: 'installed' }, writable: false }] } });
+  }
+  const m = u.match(/^\/api\/v1\/packages\/([^/]+)\/customizations$/);
+  if (m) {
+    if (customizationsFail) {
+      return json(503, { success: false, error: { code: 'SERVICE_UNAVAILABLE', message: 'The customization ledger is unavailable.' } });
+    }
+    return json(200, { success: true, data: decodeURIComponent(m[1]) === BASE ? HOTCRM_READ : EMPTY_READ });
+  }
+  if (u.startsWith('/api/v1/data/sys_metadata_activation')) {
+    return json(200, { object: 'sys_metadata_activation', records: [], hasMore: false });
+  }
+  return json(404, { success: false });
+});
+
+beforeEach(() => {
+  customizationsFail = false;
+  fetchMock.mockClear();
+  vi.stubGlobal('fetch', fetchMock);
+});
+afterEach(() => {
+  cleanup();
+  vi.unstubAllGlobals();
+});
+
+const area = (packageId: string | null): MetadataAreaHost => ({
+  packageId,
+  readOnly: packageId !== null,
+  basePath: `/studio/${packageId ?? '~all'}/metadata`,
+});
+
+function mountList(host: MetadataAreaHost | null, type: string, search: string) {
+  const base = host?.basePath ?? '/apps/setup/metadata';
+  const tree = (
+    <MemoryRouter initialEntries={[`${base}/${type}${search}`]}>
+      <MetadataResourceListPage type={type} />
+    </MemoryRouter>
+  );
+  return render(host ? <MetadataAreaHostContext.Provider value={host}>{tree}</MetadataAreaHostContext.Provider> : tree);
+}
+
+function mountDirectory(host: MetadataAreaHost) {
+  return render(
+    <MetadataAreaHostContext.Provider value={host}>
+      <MemoryRouter initialEntries={[`${host.basePath}?package=${host.packageId}`]}>
+        <MetadataDirectoryPage />
+      </MemoryRouter>
+    </MetadataAreaHostContext.Provider>,
+  );
+}
+
+const marksOf = (rowName: string) =>
+  within(screen.getByTestId(`metadata-row-${rowName}`))
+    .queryAllByTestId('customization-mark')
+    .map((m) => `${m.getAttribute('data-kind')}:${m.textContent}`);
+const customizationReads = () =>
+  fetchMock.mock.calls.filter(([u]) => String(u).endsWith('/customizations')).map(([u]) => String(u));
+
+describe('the All metadata lists mark a base\'s customizations (objectstack#28568)', () => {
+  it('the translation list marks the served override "Customized (HotCRM)", and the filter shows it alone', async () => {
+    mountList(area(BASE), 'translation', `?package=${BASE}`);
+    const only = await screen.findByTestId('metadata-only-customizations');
+    expect(marksOf('crm_en')).toEqual([`customized:${tFormat('engine.customizationMark.customized', 'en-US', { base: 'HotCRM' })}`]);
+    expect(marksOf('crm_en')).toEqual(['customized:Customized (HotCRM)']);
+    // CONTROL: the base's item the read does not list carries no mark.
+    expect(marksOf('crm_de')).toEqual([]);
+    // Another package's row stays out of the base's list, as before.
+    expect(screen.queryByTestId('metadata-row-plain_en')).toBeNull();
+
+    expect(only).toHaveTextContent(tFormat('engine.list.customizations.only', 'en-US', { marked: 1 }));
+    fireEvent.click(only);
+    expect(screen.getByTestId('metadata-row-crm_en')).toBeInTheDocument();
+    expect(screen.queryByTestId('metadata-row-crm_de')).toBeNull();
+    fireEvent.click(only);
+    expect(screen.getByTestId('metadata-row-crm_de')).toBeInTheDocument();
+  });
+
+  it('the email-template list holds the pair\'s item beside the base\'s, marked "Added"', async () => {
+    mountList(area(BASE), 'email_template', `?package=${BASE}`);
+    await screen.findByTestId('metadata-only-customizations');
+    expect(marksOf('renewal_notice')).toEqual([`added:${t('engine.customizationMark.added', 'en-US')}`]);
+    // The read overrides `welcome` in zh-CN only: the en member is the base's own.
+    expect(marksOf('welcome')).toEqual([]);
+  });
+
+  it('a failed read draws no mark and no filter, and says the server\'s sentence', async () => {
+    customizationsFail = true;
+    mountList(area(BASE), 'email_template', `?package=${BASE}`);
+    const failed = await screen.findByTestId('metadata-customizations-failed');
+    expect(failed).toHaveTextContent('The customization ledger is unavailable.');
+    // The pair's item is still listed (the list read is its own), unmarked.
+    expect(marksOf('renewal_notice')).toEqual([]);
+    expect(screen.queryByTestId('metadata-only-customizations')).toBeNull();
+  });
+
+  it('a base without a pair is unchanged: no mark, no filter', async () => {
+    mountList(area(PLAIN), 'translation', `?package=${PLAIN}`);
+    await screen.findByTestId('metadata-row-plain_en');
+    await vi.waitFor(() => expect(customizationReads()).toEqual([`/api/v1/packages/${PLAIN}/customizations`]));
+    // Let the read's answer render, then look.
+    await new Promise((r) => setTimeout(r, 0));
+    expect(marksOf('plain_en')).toEqual([]);
+    expect(screen.queryByTestId('metadata-only-customizations')).toBeNull();
+    expect(screen.queryByTestId('metadata-customizations-failed')).toBeNull();
+  });
+
+  it('CONTROL: Setup (no area) reads no customizations and marks nothing', async () => {
+    mountList(null, 'translation', `?package=${BASE}`);
+    await screen.findByTestId('metadata-row-crm_en');
+    expect(marksOf('crm_en')).toEqual([]);
+    expect(customizationReads()).toEqual([]);
+  });
+
+  it('the cross-package leg labels an item of a pair with its base', async () => {
+    mountList(area(null), 'permission', '?scope=environment');
+    await screen.findByTestId('metadata-row-crm_rep_plus');
+    expect(marksOf('crm_rep_plus')).toEqual([
+      `customizationOf:${tFormat('engine.customizationMark.customizationOf', 'en-US', { base: BASE })}`,
+    ]);
+    // CONTROL: the base's own item names no base.
+    expect(marksOf('crm_rep')).toEqual([]);
+    expect(customizationReads()).toEqual([]);
+  });
+});
+
+describe('the All metadata directory counts a base\'s customizations (objectstack#28568)', () => {
+  it('the object tile counts the extension, the translation tile its override, and the header the total', async () => {
+    mountDirectory(area(BASE));
+    const total = await screen.findByTestId('directory-customizations-total');
+    expect(total).toHaveTextContent(
+      tFormat('engine.directory.customizations.total', 'en-US', { customized: 3, base: 'HotCRM' }),
+    );
+    expect(screen.getByTestId('directory-tile-customized-object')).toHaveTextContent(
+      tFormat('engine.directory.customizations.tile', 'en-US', { customized: 1 }),
+    );
+    expect(screen.getByTestId('directory-tile-customized-translation')).toHaveTextContent('1 customized');
+    expect(screen.getByTestId('directory-tile-customized-email_template')).toHaveTextContent('1 customized');
+    // CONTROL: a type with no served customization draws no number, not "0".
+    expect(screen.queryByTestId('directory-tile-customized-permission')).toBeNull();
+  });
+
+  it('a failed read draws no number, never "0", and says the server\'s sentence', async () => {
+    customizationsFail = true;
+    mountDirectory(area(BASE));
+    expect(await screen.findByTestId('directory-customizations-failed')).toHaveTextContent(
+      'The customization ledger is unavailable.',
+    );
+    expect(screen.queryByTestId('directory-customizations-total')).toBeNull();
+    expect(screen.queryAllByTestId(/^directory-tile-customized-/)).toEqual([]);
+  });
+});
@@ -0,0 +1,83 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * objectstack#28568 — which mark a row of a base's lists carries, and the
+ * per-type numbers of the directory, from the served customization read only
+ * (ADR-0146 D3; no diff, no `basedOn` verdict, D2/D6).
+ */
+
+import { describe, it, expect } from 'vitest';
+import {
+  customizationBaseOfRow,
+  customizationCountsByType,
+  customizationMarkOf,
+  customizationTotal,
+  indexCustomizations,
+} from './customizationMarks';
+import type { PackageCustomizations } from './packageCustomizations-io';
+
+const READ: PackageCustomizations = {
+  packageId: 'hotcrm',
+  overrides: [
+    { type: 'translation', name: 'crm_en' },
+    { type: 'email_template', name: 'welcome', member: 'zh-CN' },
+    { type: 'object', name: 'crm_account' },
+  ],
+  extensions: [
+    { object: 'crm_account', kind: 'field', name: 'tier__c' },
+    { object: 'crm_lead', kind: 'index', fields: ['email'] },
+  ],
+  switchedOff: [{ type: 'flow', name: 'nightly_sync' }],
+  counts: { overrides: 3, extensions: 2, switchedOff: 1 },
+};
+const index = indexCustomizations('hotcrm', READ)!;
+
+describe('customizationMarkOf (objectstack#28568)', () => {
+  it('a served override is "customized", whether served under the base or the pair', () => {
+    expect(customizationMarkOf({ type: 'translation', name: 'crm_en', packageId: 'hotcrm' }, index)).toBe('customized');
+    expect(customizationMarkOf({ type: 'translation', name: 'crm_en', packageId: 'hotcrm.custom' }, index)).toBe('customized');
+  });
+
+  it('an override of a pair-identified type marks its own member only', () => {
+    expect(customizationMarkOf({ type: 'email_template', name: 'welcome', member: 'zh-CN', packageId: 'hotcrm' }, index)).toBe('customized');
+    expect(customizationMarkOf({ type: 'email_template', name: 'welcome', member: 'en', packageId: 'hotcrm' }, index)).toBeNull();
+    expect(customizationMarkOf({ type: 'email_template', name: 'welcome', packageId: 'hotcrm' }, index)).toBeNull();
+  });
+
+  it('any other item of the pair is "added"; the base\'s own items and other packages carry nothing', () => {
+    expect(customizationMarkOf({ type: 'translation', name: 'crm_fr', packageId: 'hotcrm.custom' }, index)).toBe('added');
+    expect(customizationMarkOf({ type: 'translation', name: 'crm_de', packageId: 'hotcrm' }, index)).toBeNull();
+    // The type is part of the identity: a same-named item of another type is not the override.
+    expect(customizationMarkOf({ type: 'view', name: 'crm_en', packageId: 'hotcrm' }, index)).toBeNull();
+    expect(customizationMarkOf({ type: 'translation', name: 'crm_en', packageId: 'com.example.other' }, index)).toBeNull();
+    expect(customizationMarkOf({ type: 'translation', name: 'crm_en' }, index)).toBeNull();
+  });
+
+  it('a customization package has no pair to index', () => {
+    expect(indexCustomizations('hotcrm.custom', { ...READ, packageId: 'hotcrm.custom' })).toBeNull();
+  });
+});
+
+describe('the directory\'s numbers (objectstack#28568)', () => {
+  it('per type: the served overrides, and the extensions (members) on object', () => {
+    expect(customizationCountsByType(READ)).toEqual({ translation: 1, email_template: 1, object: 3 });
+  });
+
+  it('the total is the served overrides plus the served extensions, the landing\'s "customized"', () => {
+    expect(customizationTotal(READ)).toBe(5);
+  });
+
+  it('an empty read counts nothing', () => {
+    const empty = { ...READ, overrides: [], extensions: [], counts: { overrides: 0, extensions: 0, switchedOff: 1 } };
+    expect(customizationCountsByType(empty)).toEqual({});
+    expect(customizationTotal(empty)).toBe(0);
+  });
+});
+
+describe('customizationBaseOfRow (objectstack#28568)', () => {
+  it('names the base of a pair id, and nothing else', () => {
+    expect(customizationBaseOfRow('hotcrm.custom')).toBe('hotcrm');
+    expect(customizationBaseOfRow('hotcrm')).toBeNull();
+    expect(customizationBaseOfRow(undefined)).toBeNull();
+  });
+});