Extends api.ts with the Phase 3.5 wire types (InstanceRole, Scope,
MeDto, AdminDto, ApiKeyDto, MintApiKey*) and the matching apiKeys
namespace. AdminUser in auth.ts now carries instance_role and email,
so layout/store consumers see the role without a separate fetch.
Adds two tiny lib helpers used by the upcoming profile/users pages:
RoleChip.svelte for the colored owner/admin/member pill, and
password-gen.ts for crypto.getRandomValues-backed temporary
passwords used in user-invite + reset-password reveals.
AdminUserRecord stays as a deprecated alias until /admins is
retired in a follow-up commit.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>