API de membresías

withPermissionRoute(req, {
  permission: 'team.read',    // reads
  permission: 'team.invite',  // invitations
  permission: 'team.manage',  // updates, removals
}, handler)

interface Membership {
  id: string;
  organizationId: string;
  userId: string;
  user: { id: string; name: string; email: string; };
  role: 'admin' | 'member';
  status: 'active' | 'invited' | 'suspended';
  accessGroupIds: string[];
  invitedAt: string | null;
  joinedAt: string | null;
  createdAt: string;
}

1. Admin: POST /api/memberships { email, accessGroupId }
   → status: 'invited', invitedAt = now()
   → Email sent with invite link

2. Invitee clicks link → GET /api/auth/invite?token=...
   → status: 'active', joinedAt = now()
   → User created (if first login)

3. Admin: DELETE /api/memberships/[id]
   → Removes membership (cascade: removes from access groups)
   → User loses org access immediately

// Body: { accessGroupIds: string[] }
// This REPLACES the member's group assignments entirely
// Validates all group IDs belong to the same organization
// Records change in permission audit log