feat(settings): complete remaining settings tabs (account, tags, turns)

Fill the three previously-placeholder settings sections so every menu item
is now a real page inside the settings shell:

- حساب کاربری: new authenticated POST /api/v1/user/change-password
  (verifies current password, ≥8 chars, must differ) + account page with a
  profile summary and change-password form.
- برچسب‌ها: new per-tenant TenantTag domain (entity/repo/controller +
  migration) with tenant-scoped CRUD at /api/v1/tenant-tag(s), plus a tags
  management page (list + color + add/edit/delete).
- مدیریت نوبت دهی: export the existing WeeklyScheduleTab from
  DoctorDetailPage and reuse it in a standalone AppointmentSettingsPage
  (current doctor's uuid + addresses).

Wire all three menu entries to their routes. Backend covered by PHPUnit
(change-password, tenant-tag CRUD + ownership); FE covered by Vitest.
API docs updated (auth.md, tag.md).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

assets/admin/components/layout/SettingsLayout.test.tsx

@@ -26,14 +26,14 @@ describe('SettingsLayout', () => {
     expect(active).toHaveAttribute('href', '/admin/subscription');
   });
 
-  it('renders not-yet-implemented items as disabled placeholders', () => {
+  it('renders every menu item as a navigable link', () => {
     renderWithProviders(
       <SettingsLayout active="subscription"><div /></SettingsLayout>,
     );
-    // "حساب کاربری" has no route → disabled button with "به‌زودی"
-    const account = screen.getByText('حساب کاربری').closest('button');
-    expect(account).toBeDisabled();
-    expect(screen.getAllByText('به‌زودی').length).toBeGreaterThan(0);
+    // all items are now wired to a route
+    expect(screen.getByText('مدیریت نوبت دهی').closest('a')).toHaveAttribute('href', '/admin/appointment-settings');
+    expect(screen.getByText('برچسب‌ها').closest('a')).toHaveAttribute('href', '/admin/tags-settings');
+    expect(screen.queryByText('به‌زودی')).not.toBeInTheDocument();
   });
 
   it('filters the menu by the search query', () => {