add User persistence: model, migration, eloquent + fake repo
UserModel maps users table (id, email unique, password_hash,
is_admin bool default false). EloquentUserRepository implements
UserRepository: create from CreateUserDto, find by id,
findByEmail. toDomain() materializes a User entity wrapping email
in EmailAddress vo. FakeUserRepository: in-memory map keyed by
auto-incrementing id, returns defensive copies on read (per
youngstartup pattern). composer stan script now passes
--no-progress for cleaner ci output.
eca73213f5
