feat(mobile): show entity name in mobile topbar on detail pages

Detail pages (clients, yachts, companies, berths, invoices, expenses)
now push their entity name + a back-button toggle to the mobile
topbar via useMobileChrome, replacing the URL UUID fallback that was
rendering before.

Supporting changes:
  - useMobileChrome() no longer throws when called outside the
    MobileLayoutProvider — desktop-tree consumers get a no-op
    setChrome so callers don't have to branch on shell type.
  - setChrome is now stable across renders (useCallback) so callers'
    useEffect dependency arrays don't infinite-loop.
  - DetailPageShell now also pushes its entityName + cleans up on
    unmount, and hides its desktop-only sticky header on mobile so it
    doesn't double up with the topbar (no current callers, prep for
    Phase 4 migration).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/companies/company-detail.tsx

@@ -1,9 +1,11 @@
 'use client';
 
+import { useEffect } from 'react';
 import { useQuery } from '@tanstack/react-query';
 import { useParams } from 'next/navigation';
 
 import { DetailLayout } from '@/components/shared/detail-layout';
+import { useMobileChrome } from '@/components/layout/mobile/mobile-layout-provider';
 import { CompanyDetailHeader } from '@/components/companies/company-detail-header';
 import { getCompanyTabs } from '@/components/companies/company-tabs';
 import { useRealtimeInvalidation } from '@/hooks/use-realtime-invalidation';
@@ -45,6 +47,13 @@ export function CompanyDetail({ companyId, currentUserId }: CompanyDetailProps)
       apiFetch<{ data: CompanyData }>(`/api/v1/companies/${companyId}`).then((r) => r.data),
   });
 
+  const { setChrome } = useMobileChrome();
+  const titleForChrome: string | null = data?.name ?? null;
+  useEffect(() => {
+    setChrome({ title: titleForChrome, showBackButton: true });
+    return () => setChrome({ title: null, showBackButton: false });
+  }, [titleForChrome, setChrome]);
+
   useRealtimeInvalidation({
     'company:updated': [['companies', companyId]],
     'company:archived': [['companies', companyId]],