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>

packages/types/src/auth.ts

@@ -40,6 +40,12 @@ export interface LoginRequest {
   password: string;
 }
 
+export interface ScopeOrganization {
+  id: string;
+  slug: string;
+  name: string;
+}
+
 export interface LoginResponse {
   token: string;
   admin: {
@@ -48,6 +54,8 @@ export interface LoginResponse {
     role: AdminRole;
     tenantId: string;
     tenantSlug: string;
+    tenantName: string;
+    organization: ScopeOrganization | null;
   };
 }
 
@@ -66,4 +74,6 @@ export interface AdminProfile {
   role: AdminRole;
   tenantId: string;
   tenantSlug: string;
+  tenantName: string;
+  organization: ScopeOrganization | null;
 }