fix(settings): every settings page renders the settings shell

Resources, branches, price lists, holidays and the new categories page sat
in the settings menu but rendered bare, so clicking one made the settings
sidebar disappear — the subscription page was the only one that kept it.

Eleven pages now wrap in SettingsLayout with the key of the menu entry they
belong to, and the four resource pages (list, types, skills, pools) share
one menu entry plus a sub-nav between them, rather than four entries that
would make the menu a third longer without making anything clearer.

.seg accepts `a` as well as `button`, and treats `active` as an alias of
`on`. Both were needed: cross-page tabs must be real links, and the pages
already using `active` (service detail, clinic appointment settings) had no
visible highlight at all.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

assets/admin/pages/ResourceDetailPage.tsx

@@ -9,6 +9,7 @@ import ResourceExceptionsPanel from '../components/resources/ResourceExceptionsP
 import ResourceServicesPanel from '../components/resources/ResourceServicesPanel';
 import ResourceSkillsPanel from '../components/resources/ResourceSkillsPanel';
 import ResourceCategoriesPanel from '../components/resources/ResourceCategoriesPanel';
+import SettingsLayout from '../components/layout/SettingsLayout';
 import { useUrlState } from '../hooks/useUrlState';
 import { usePermissions } from '../hooks/usePermissions';
 import { useBranches } from '../hooks/useBranches';
@@ -56,10 +57,20 @@ export default function ResourceDetailPage() {
 
   const [editOpen, setEditOpen] = useState(false);
 
-  if (loading) return <div style={{ padding: 24, color: 'var(--text-3)', fontSize: 13 }}>در حال بارگذاری...</div>;
-  if (!resource) return <div style={{ padding: 24, color: 'var(--text-3)', fontSize: 13 }}>منبع یافت نشد.</div>;
+  // حالت‌های بارگذاری و نبودِ منبع هم داخل پوستهٔ تنظیمات می‌مانند، وگرنه منوی کناری
+  // یک لحظه می‌پرد و دوباره برمی‌گردد.
+  if (loading || !resource) {
+    return (
+      <SettingsLayout active="resources">
+        <div style={{ padding: 24, color: 'var(--text-3)', fontSize: 13 }}>
+          {loading ? 'در حال بارگذاری...' : 'منبع یافت نشد.'}
+        </div>
+      </SettingsLayout>
+    );
+  }
 
   return (
+    <SettingsLayout active="resources">
     <div className="fade-in">
       <PageHeader
         title={resource.name}
@@ -142,6 +153,7 @@ export default function ResourceDetailPage() {
         }
       />
     </div>
+    </SettingsLayout>
   );
 }