Replace HunyuanSamplingParam and FastHunyuanSamplingParam subclasses
with profile-based defaults. This adds the profile infrastructure
(ConfigInfo.default_profile, SamplingParam._from_profile) and the
first profile definitions for Hunyuan models, enabling future model
families to migrate from subclass overrides to declarative profiles.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>