sections are paths, not a query string

The admin declares its routes in the manifest, so /fofos-admin/layout/header and
/fofos-admin/pages/home are real URLs. One reader takes the two segments after
the mount; links carry no query string at all, so nothing leaks between
sections.

What stays in the query is how you are looking — device, tab, view — rather than
at what.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

web/DetailHeader.tsx

@@ -1,5 +1,5 @@
-import { useSearchParams } from 'react-router';
-import { DEFAULT_SECTION, isSectionKey, sectionFor } from './sections';
+import { useNav } from './routes';
+import { sectionFor } from './sections';
 
 /**
  * The detail panel's chrome header — the section's own name, not the word "Detail".
@@ -26,9 +26,8 @@ import { DEFAULT_SECTION, isSectionKey, sectionFor } from './sections';
  * area and always reachable.
  */
 export const DetailHeader = () => {
-  const [params] = useSearchParams();
-  const raw = params.get('section');
-  const section = sectionFor(isSectionKey(raw) ? raw : DEFAULT_SECTION);
+  const { section: key } = useNav();
+  const section = sectionFor(key);
   const Icon = section.icon;
 
   return (