@@ -17,22 +17,26 @@ import type { Page } from '@objectstack/spec/ui';
  *
  * Strategy
  * --------
- *  - `kind: 'slotted'` + `isDefault: true`: overrides `highlights`,
- *    `details`, `tabs` and `discussion`. Header / actions fall through
+ *  - `kind: 'slotted'` + `isDefault: true`: overrides `alerts`,
+ *    `highlights`, `tabs` and `discussion`. Header / actions fall through
  *    to the synthesizer so the object's declared actions
  *    (`update_my_profile / change_my_password / resend_verification_email
  *    / ban_user / impersonate_user / …`) still appear
  *    in the header overflow menu automatically.
  *  - `highlights` promotes the four signals worth scanning at the top:
  *    email, verification state, 2FA, platform role. Highlight fields
  *    are auto-dropped from the details grid below.
- *  - `details` re-groups remaining fields into sections and hides
- *    admin-internal audit columns. Banned / ban metadata is still
- *    editable from the header actions — we just don't show it in
- *    every user's body.
- *  - `tabs` is **explicitly curated** to the 5 related lists that matter
- *    on a user profile (Positions / Sessions / Linked Accounts / Organizations /
- *    Personal OAuth Apps). Without this override, the synthesizer
+ *  - The FIRST `tabs` item is the details grid: a `record:details` that
+ *    re-groups remaining fields into sections and hides admin-internal
+ *    audit columns. Banned / ban metadata is still editable from the
+ *    header actions — we just don't show it in every user's body. It is
+ *    a tab item and not a `details` slot because the `tabs` slot replaces
+ *    the whole tab strip the Details tab lives in: a `details` slot beside
+ *    `tabs` never rendered, and `PageSchema` refuses the pair.
+ *  - The other `tabs` items are **explicitly curated** to the related lists
+ *    that matter on a user profile (Positions / Permission Sets / Business
+ *    Units / Sessions / Linked Accounts / Organizations / OAuth Apps / API
+ *    Keys) plus a Security tab. Without this override, the synthesizer
  *    auto-generates a tab per object that has a FK to sys_user
  *    (sys_position.created_by, sys_email.updated_by, sys_user_preference,
  *    sys_email_template.created_by, …) producing dozens of noisy
@@ -125,47 +129,61 @@ export const SysUserDetailPage: Page = {
       },
     },
 
-    // ── Body / details grid ───────────────────────────────────────
-    details: {
-      type: 'record:details',
-      properties: {
-        hideFields: [
-          'id',
-          'banned',
-          'ban_reason',
-          'ban_expires',
-          // already promoted to highlights:
-          'email',
-          'phone_number',
-          'email_verified',
-          'two_factor_enabled',
-          'role',
-        ],
-        sections: [
-          {
-            label: { en: 'Identity', 'zh-CN': '身份', 'ja-JP': 'アイデンティティ', 'es-ES': 'Identidad' },
-            fields: ['name', 'image'],
-          },
-          {
-            label: { en: 'Audit', 'zh-CN': '审计', 'ja-JP': '監査', 'es-ES': 'Auditoría' },
-            fields: ['created_at', 'updated_at'],
-          },
-        ],
-      },
-    },
-
-    // ── Tabs: curated related lists ───────────────────────────────
-    // Only the 4 lists that are semantically about THIS user account.
+    // ── Tabs: the details grid, then curated related lists ────────
+    // Only the lists that are semantically about THIS user account.
     // Everything else (sys_position created_by, sys_email_template
     // updated_by, …) is incidental authorship metadata and would only
     // create noise.
+    //
+    // There is no `details` slot: the `tabs` slot replaces the whole tab
+    // strip the synthesized Details tab lives in, so a `details` slot beside
+    // it never rendered and `PageSchema` refuses the pair (#22568). The
+    // details grid is therefore the FIRST tab's body here.
     tabs: {
       type: 'page:tabs',
       properties: {
         // `tabStyle`, not `type` (#6776) — see sys-organization.page.ts.
         tabStyle: 'line',
         position: 'top',
         items: [
+          {
+            // ── Body / details grid ───────────────────────────────
+            // Re-groups the remaining fields into sections and hides
+            // admin-internal columns. Banned / ban metadata is still
+            // editable from the header actions — it is just not shown in
+            // every user's body.
+            label: { en: 'Details', 'zh-CN': '详情', 'ja-JP': '詳細', 'es-ES': 'Detalles' },
+            icon: 'file-text',
+            children: [
+              {
+                type: 'record:details',
+                properties: {
+                  hideFields: [
+                    'id',
+                    'banned',
+                    'ban_reason',
+                    'ban_expires',
+                    // already promoted to highlights:
+                    'email',
+                    'phone_number',
+                    'email_verified',
+                    'two_factor_enabled',
+                    'role',
+                  ],
+                  sections: [
+                    {
+                      label: { en: 'Identity', 'zh-CN': '身份', 'ja-JP': 'アイデンティティ', 'es-ES': 'Identidad' },
+                      fields: ['name', 'image'],
+                    },
+                    {
+                      label: { en: 'Audit', 'zh-CN': '审计', 'ja-JP': '監査', 'es-ES': 'Auditoría' },
+                      fields: ['created_at', 'updated_at'],
+                    },
+                  ],
+                },
+              },
+            ],
+          },
           {
             label: { en: 'Positions', 'zh-CN': '岗位', 'ja-JP': 'ポジション', 'es-ES': 'Puestos' },
             icon: 'shield-check',
 
@@ -56,7 +56,13 @@ import {
   checkListViewCalendarVisualization,
   checkListViewChartBinding,
 } from './view.zod';
-import { PageSchema, checkPageSourceCompleteness, checkPageRequiresKind, checkPagePrintComposition } from './page.zod';
+import {
+  PageSchema,
+  checkPageSourceCompleteness,
+  checkPageRequiresKind,
+  checkPagePrintComposition,
+  checkPageSlotPair,
+} from './page.zod';
 import {
   GlobalFilterSchema,
   checkGlobalFilterDateDefaultValue,
@@ -271,6 +277,28 @@ const pagePrintFixtures: Fixture[] = [
   { label: 'a `slotted` page with no `print`', value: { ...PAGE_BASE, kind: 'slotted' }, refusesAt: [] },
 ];
 
+// [#22568] `slots.details` beside `slots.tabs` is refused at `slots.details`:
+// the `tabs` slot replaces the strip the Details tab lives in, so the
+// `details` body never rendered. Every fixture is a `record` page with no
+// `print`, `source` or `requires`, so the three siblings stay silent and each
+// row exercises THIS check alone; the kind-less row is the one whose direct
+// call sees no `kind` while the parse sees the applied `full` default.
+const SLOT_DETAILS = { type: 'record:details', properties: { hideFields: ['id'] } } as const;
+const SLOT_TABS = {
+  type: 'page:tabs',
+  properties: { items: [{ label: 'Related', children: [{ type: 'record:related_list' }] }] },
+} as const;
+const SLOT_PAGE = { ...PAGE_BASE, type: 'record', object: 'account', kind: 'slotted' } as const;
+const pageSlotPairFixtures: Fixture[] = [
+  { label: '`details` beside `tabs`, one component each', value: { ...SLOT_PAGE, slots: { details: SLOT_DETAILS, tabs: SLOT_TABS } }, refusesAt: ['slots.details'] },
+  { label: '`details` beside `tabs`, each an array', value: { ...SLOT_PAGE, slots: { details: [SLOT_DETAILS], tabs: [SLOT_TABS] } }, refusesAt: ['slots.details'] },
+  { label: 'an EMPTY `details: []` beside `tabs` — a present slot is refused, not its contents', value: { ...SLOT_PAGE, slots: { details: [], tabs: SLOT_TABS } }, refusesAt: ['slots.details'] },
+  { label: '`details` beside `tabs` on a page with no `kind` (the `full` default)', value: { ...PAGE_BASE, type: 'record', object: 'account', slots: { details: SLOT_DETAILS, tabs: SLOT_TABS } }, refusesAt: ['slots.details'] },
+  { label: '`details` alone', value: { ...SLOT_PAGE, slots: { details: SLOT_DETAILS } }, refusesAt: [] },
+  { label: '`tabs` alone, carrying the `record:details` in its first item', value: { ...SLOT_PAGE, slots: { tabs: { type: 'page:tabs', properties: { items: [{ label: 'Details', children: [SLOT_DETAILS] }] } } } }, refusesAt: [] },
+  { label: 'a slot map with neither', value: { ...SLOT_PAGE, slots: { discussion: [] } }, refusesAt: [] },
+];
+
 const DATE_FILTER = { field: 'created_at', type: 'date' } as const;
 
 const dateDefaultFixtures: Fixture[] = [
@@ -485,6 +513,7 @@ const MIRRORED: MirroredSchema[] = [
       { name: 'checkPageSourceCompleteness', check: checkPageSourceCompleteness, fixtures: pageSourceFixtures },
       { name: 'checkPageRequiresKind', check: checkPageRequiresKind, fixtures: pageRequiresFixtures },
       { name: 'checkPagePrintComposition', check: checkPagePrintComposition, fixtures: pagePrintFixtures },
+      { name: 'checkPageSlotPair', check: checkPageSlotPair, fixtures: pageSlotPairFixtures },
     ],
     cleanFixtures: [{ ...PAGE_BASE }],
   },
@@ -640,9 +669,9 @@ describe('each schema attaches its export BY IDENTIFIER — no inline copy', ()
     expect(attachments(src, 'checkListViewPageMount')).toBe(0);
   });
 
-  it('page.zod.ts declares all three exports and attaches each to PageSchema', () => {
+  it('page.zod.ts declares all four exports and attaches each to PageSchema', () => {
     const src = read('page.zod.ts');
-    for (const name of ['checkPageSourceCompleteness', 'checkPageRequiresKind', 'checkPagePrintComposition']) {
+    for (const name of ['checkPageSourceCompleteness', 'checkPageRequiresKind', 'checkPagePrintComposition', 'checkPageSlotPair']) {
       expect(src).toContain(`export function ${name}(`);
       expect(declarations(src, name)).toBe(1);
       expect(attachments(src, name)).toBe(1);
@@ -676,6 +705,7 @@ describe('`./index` (the `@objectstack/spec/ui` surface) exports the same functi
     ['checkPageSourceCompleteness', checkPageSourceCompleteness],
     ['checkPageRequiresKind', checkPageRequiresKind],
     ['checkPagePrintComposition', checkPagePrintComposition],
+    ['checkPageSlotPair', checkPageSlotPair],
     ['checkGlobalFilterDateDefaultValue', checkGlobalFilterDateDefaultValue],
   ] as const)('%s — reference identity, and the `(value, ctx)` arity', (name, fn) => {
     expect((ui as Record<string, unknown>)[name]).toBe(fn);
 
@@ -744,6 +744,55 @@ export function checkPageRequiresKind(
   });
 }
 
+/**
+ * The slot-pair check attached to {@link PageSchema}: a page that authors
+ * both `slots.details` and `slots.tabs` is refused at `slots.details`, naming
+ * the pair and the fix.
+ *
+ * The two slots are not independent, whatever the slot menu's layout
+ * suggests. On a slotted record page the `details` slot is the BODY of the
+ * Details tab, and that tab lives inside the synthesized `page:tabs` strip;
+ * the `tabs` slot replaces that whole strip. So a `details` authored beside a
+ * `tabs` has nowhere to render: the console's default-page synthesizer reads
+ * `tabs` and never reads `details` (its own doc states the precedence — "wins
+ * over `details` when both are provided"). Before this check the pair parsed,
+ * validated and saved, and the authored details body — its `sections`, its
+ * `hideFields` — silently never applied. The fix is the shape the platform's
+ * own `sys_user_detail` page uses: the `record:details` component as a child
+ * of a `tabs` item (the first one, by convention), and no `details` slot.
+ *
+ * Judged on the slot map whatever the page's `kind`: the pair is never a
+ * coherent declaration, and a page that is not slotted reads no slot at all.
+ * A slot is present when its value is not `undefined` — the synthesizer's own
+ * test — so an empty `details: []` beside `tabs` is refused like a full one.
+ *
+ * Exported for the reason {@link checkPageSourceCompleteness} is: a downstream
+ * mirror that derives its schema from `PageSchema.shape` drops every
+ * object-level check, and re-attaches this one with
+ * `.superRefine(checkPageSlotPair)`. `PageSchema` attaches this same binding —
+ * pinned in `object-refinement-check-exports.test.ts`.
+ */
+export function checkPageSlotPair(
+  page: { slots?: unknown },
+  ctx: z.RefinementCtx,
+): void {
+  const slots = page.slots;
+  if (slots === undefined || slots === null || typeof slots !== 'object') return;
+  const { details, tabs } = slots as { details?: unknown; tabs?: unknown };
+  if (details === undefined || tabs === undefined) return;
+  ctx.addIssue({
+    code: 'custom',
+    path: ['slots', 'details'],
+    message:
+      '`slots.details` and `slots.tabs` are refused together: the `details` slot is the body of the '
+      + 'Details tab inside the synthesized `page:tabs` strip, and an authored `tabs` slot replaces that '
+      + 'whole strip, so the `details` beside it is never rendered. Move the `record:details` component '
+      + 'into the `tabs` items — as the `children` of the first item, e.g. '
+      + "`{ label: 'Details', children: [{ type: 'record:details', properties: { … } }] }` — and delete "
+      + '`slots.details`. To keep the synthesized tabs instead, delete `slots.tabs`.',
+  });
+}
+
 /**
  * Page Schema
  * Defines a composition of components for a specific context.
@@ -1285,6 +1334,15 @@ export const PageSchema = lazySchema(() => strictObject({
    * custom, call the corresponding `buildDefault*` sub-builder from the
    * renderer runtime (e.g. @object-ui/plugin-detail).
    *
+   * Precedence — `details` and `tabs` are NOT independent. `details`
+   * replaces the body of the Details tab, and that tab lives inside the
+   * synthesized `page:tabs` strip; `tabs` replaces the whole strip, so it
+   * wins and a `details` beside it is never rendered. A page authoring both
+   * is therefore refused ({@link checkPageSlotPair}): to replace the tabs
+   * AND the details body, put the `record:details` component in the `tabs`
+   * items (the first item's `children`, by convention) and author no
+   * `details` slot.
+   *
    * Only honored when `kind === 'slotted'`.
    */
   slots: strictObject({
@@ -1355,10 +1413,15 @@ export const PageSchema = lazySchema(() => strictObject({
   .superRefine(checkPageRequiresKind)
   // Ruling B′ on #8346 (#22158): a print page prints exactly the blocks it
   // authors. Attached by identifier for the same reason as the checks above.
-  .superRefine(checkPagePrintComposition));
-// PageSchema's cross-field rules are the three checks above: the
+  .superRefine(checkPagePrintComposition)
+  // #22568: `slots.details` beside `slots.tabs` never renders — the `tabs`
+  // slot replaces the strip the Details tab lives in. Attached by identifier
+  // for the same reason as the checks above.
+  .superRefine(checkPageSlotPair));
+// PageSchema's cross-field rules are the four checks above: the
 // ADR-0080/0081 source completeness check, the compiled-kind `requires`
-// check and the print-page composition check. It once also required
+// check, the print-page composition check and the `details` + `tabs` slot
+// pair check. It once also required
 // `recordReview`/`blankLayout` and `slots` (all removed — unrendered roadmap /
 // "required-but-unauthorable" Studio traps).