fix(example-showcase): project-detail 的 tab token 改用声明的 value (#5776)

`page:tabs` 的 `items[]` 上,稳定的 `?tab=` URL token 只有一个拼法:`value`
—— 既是 `PageTabsProps.items[]` 声明的键(#5775 补上),也是 objectui tabs
renderer 唯一读的键(`containers.tsx`:非空字符串 `it.value` 才作数,否则按
下标派生)。这两个 tab 写的是 `key`,两侧都不认识:schema 是 strip 模式,parse
把它剥掉;renderer 回落到 `tab-<i>`。页面看起来正常,深链回不到原来那个 tab,
而作者拿到的是成功回执 —— ADR-0078 的教科书形状。#5068 的
`component-props-unknown-key` 闸门对这一处正好报了 2 条。

只改两行键名,零 spec / 零 objectui 改动:声明与 renderer 早已在 `value` 上一致,
错的是语料。

新增 `test/project-detail-tabs.test.ts` 同时钉形状与语义:token 写在声明的
`value` 下、能过 `PageTabsProps` 的 parse 且不被剥掉(这正是 `key` 与 `value`
的全部差别)、showcase 语料里任何 tab item 都不再出现 `key`/`id`/`name`/
`tabKey`/`slug` 这些近似拼法、token 语义且互不相同(下标派生值不具备的性质)。

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011M7UwH25Unfi73UHim7ajY

Author: claude

examples/app-showcase/src/ui/pages/project-detail.page.ts

@@ -40,7 +40,13 @@ export const ProjectDetailPage = definePage({
           {
             // Explicit details sections — each section's `fields` is a
             // field-list bound to showcase_project in the page editor.
-            key: 'details',
+            //
+            // `value` is the tab's stable `?tab=` URL token (#5776): the key
+            // `PageTabsProps.items[]` declares and objectui's tabs renderer
+            // reads. `key` was neither — an unknown prop nothing verifies and
+            // nothing reads, which left both tabs on the index-derived
+            // `tab-<i>` fallback and their deep links non-durable.
+            value: 'details',
             label: 'Details',
             children: [
               {
@@ -56,7 +62,7 @@ export const ProjectDetailPage = definePage({
             ],
           },
           {
-            key: 'tasks',
+            value: 'tasks',
             label: 'Tasks',
             children: [
               {

examples/app-showcase/test/project-detail-tabs.test.ts

@@ -0,0 +1,128 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+import { describe, it, expect } from 'vitest';
+import { PageTabsProps } from '@objectstack/spec/ui';
+
+import * as pages from '../src/ui/pages/index.js';
+import { ProjectDetailPage } from '../src/ui/pages/index.js';
+
+/**
+ * Dogfood gate for the project-detail page's tab strip (objectstack#5776).
+ *
+ * `page:tabs` items carry a **stable `?tab=` URL token**, and its one spelling
+ * is `value`: that is the key `PageTabsProps.items[]` declares (#5775) and the
+ * only one objectui's tabs renderer reads — `containers.tsx` takes a non-empty
+ * string `it.value` and otherwise derives the token from the item's index.
+ * This page authored `key` instead — a spelling neither side knows — so both
+ * tabs silently fell back to the index-derived `tab-<i>`: the page renders,
+ * and a deep link comes back to whichever tab happens to sit at that index.
+ * #5068's `component-props-unknown-key` gate reported it as exactly that, twice.
+ *
+ * The assertions pin both halves, so neither can regress in silence:
+ *  - the tokens are authored under the declared key and survive the schema's
+ *    own parse (an undeclared key would be stripped, not carried);
+ *  - `key` — and the other near-miss spellings — appear on no tab item in the
+ *    whole showcase corpus, so a later page cannot re-introduce the shape;
+ *  - the tokens are semantic and distinct, which is the property the
+ *    index-derived fallback does not have.
+ */
+
+type TabItem = Record<string, unknown> & { label?: unknown; value?: unknown };
+type AnyComponent = {
+  type?: unknown;
+  properties?: Record<string, unknown>;
+  [k: string]: unknown;
+};
+
+/** Every component on a page — regions and slots alike, nested tabs included. */
+function allComponents(page: Record<string, unknown>): AnyComponent[] {
+  const out: AnyComponent[] = [];
+  const visit = (node: unknown): void => {
+    if (!node || typeof node !== 'object' || Array.isArray(node)) return;
+    const component = node as AnyComponent;
+    out.push(component);
+    const props = component.properties;
+    if (!props) return;
+    for (const item of Array.isArray(props.items) ? props.items : []) {
+      const children = (item as TabItem)?.children;
+      for (const child of Array.isArray(children) ? children : []) visit(child);
+    }
+    for (const child of Array.isArray(props.children) ? props.children : []) visit(child);
+  };
+
+  for (const region of (page.regions as { components?: unknown[] }[] | undefined) ?? []) {
+    for (const c of region.components ?? []) visit(c);
+  }
+  for (const slot of Object.values((page.slots as Record<string, unknown>) ?? {})) {
+    for (const c of Array.isArray(slot) ? slot : [slot]) visit(c);
+  }
+  return out;
+}
+
+const tabsComponents = (page: Record<string, unknown>): AnyComponent[] =>
+  allComponents(page).filter((c) => c.type === 'page:tabs');
+
+const tabItems = (component: AnyComponent): TabItem[] =>
+  (Array.isArray(component.properties?.items) ? component.properties!.items : []) as TabItem[];
+
+/** Every page the showcase exports (the corpus the #5068 gate runs on). */
+const allPages = (Object.values(pages) as unknown[]).filter(
+  (p) =>
+    !!p && typeof p === 'object' && !Array.isArray(p) && typeof (p as { name?: unknown }).name === 'string',
+) as Record<string, unknown>[];
+
+describe('Project detail — tab tokens are authored under the declared `value` (#5776)', () => {
+  it('gives both tabs a stable `?tab=` token under `value`', () => {
+    const [tabs, ...rest] = tabsComponents(ProjectDetailPage as unknown as Record<string, unknown>);
+    expect(tabs, 'the project-detail page must carry a page:tabs component').toBeTruthy();
+    expect(rest, 'exactly one tab strip on this page').toHaveLength(0);
+
+    const items = tabItems(tabs);
+    expect(items).toHaveLength(2);
+    expect(items.map((it) => it.value)).toEqual(['details', 'tasks']);
+    for (const item of items) {
+      expect(item, `tab "${String(item.label)}" must not carry the undeclared \`key\``).not.toHaveProperty('key');
+    }
+  });
+
+  it('survives `PageTabsProps` parse with the tokens intact — a declared key is CARRIED', () => {
+    // The point of the rename: an undeclared key is dropped by the parse (strip
+    // mode) while looking authored in the source. Parsing here proves the token
+    // reaches a consumer, which is the whole difference between `key` and
+    // `value`.
+    const tabs = tabsComponents(ProjectDetailPage as unknown as Record<string, unknown>)[0]!;
+    const parsed = PageTabsProps.parse(tabs.properties);
+    expect(parsed.items.map((it) => it.value)).toEqual(['details', 'tasks']);
+  });
+
+  it('leaves no near-miss token spelling on any tab item in the showcase corpus', () => {
+    // The regression this pins is a new page (or a rewrite of this one) reaching
+    // for `key` / `id` / `name` again — every one of them renders fine and
+    // sets no token.
+    for (const page of allPages) {
+      for (const tabs of tabsComponents(page)) {
+        for (const item of tabItems(tabs)) {
+          for (const spelling of ['key', 'id', 'name', 'tabKey', 'slug'] as const) {
+            expect(
+              item,
+              `page "${String(page.name)}" tab "${String(item.label)}" must carry its token as \`value\`, not \`${spelling}\``,
+            ).not.toHaveProperty(spelling);
+          }
+        }
+      }
+    }
+  });
+
+  it('uses semantic, distinct tokens — the property the index fallback lacks', () => {
+    const values = tabItems(
+      tabsComponents(ProjectDetailPage as unknown as Record<string, unknown>)[0]!,
+    ).map((it) => it.value as string);
+    expect(new Set(values).size).toBe(values.length);
+    for (const value of values) {
+      expect(value).toMatch(/^[a-z][a-z0-9_:-]*$/);
+      // `tab-<i>` is exactly the derived fallback; authoring it back would make
+      // the token as fragile as having none.
+      expect(value).not.toMatch(/^tab-\d+$/);
+    }
+  });
+});