feat: show tenancy scope (Org → Chapter) in chapter & member portals

Surface where the logged-in user sits in the hierarchy via a ScopeCard
in the sidebar, below the brand mark.

API:
- Enrich chapter login/me responses with tenantName + organization
  (LoginResponse.admin, AdminProfile types updated)
- Add GET /my/scope returning member's chapter + organization

Web:
- ScopeCard component (Organisation row + Chapter row, themed icons)
- Chapter portal: scope from auth context, blue accent
- Member portal: scope fetched server-side in layout, emerald accent
- PortalShell gains a `scope` slot rendered under the brand

Org and admin portals intentionally omit it — org IS the scope, admin is
platform-wide.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/app/(chapter)/layout.tsx

@@ -4,6 +4,7 @@ import { useEffect } from 'react';
 import { usePathname, useRouter } from 'next/navigation';
 import { useAuth } from '@/app/_lib/auth-context';
 import { PortalShell } from '@/app/_components/portal-shell';
+import { ScopeCard } from '@/app/_components/scope-card';
 import { Search, Users, Inbox, FileText, SlidersHorizontal, Bot } from 'lucide-react';
 
 const NAV = [
@@ -32,6 +33,7 @@ export default function ChapterLayout({ children }: { children: React.ReactNode
       loading={loading}
       authed={!!admin}
       user={admin ? { email: admin.email, name: admin.name, role: admin.role, subtitle: admin.tenantName } : undefined}
+      scope={admin ? <ScopeCard accent="text-blue-600" organization={admin.organization} chapter={admin.tenantName ? { name: admin.tenantName } : null} /> : undefined}
       onLogout={() => { void logout(); router.replace('/login'); }}
     >
       {children}