[Feature]: refine hardmard code

[wenhuach21]

Feature Description

I dont' know why code this init func like this

class RotationConfig(BaseModel, BaseRotationConfig):
"""Unified configuration for Hadamard rotation/transform applied to a model.

See the module docstring for a description of the three backends.

Notes:
    * ``block_size`` is the group/block size for grouped Hadamard.
      For ``backend="inplace"`` it is forwarded as ``group_size``
      (``None`` / ``-1`` means full-dimension Hadamard).
"""

# Registry key consumed by BaseRotation.from_config (kept for API parity
# with other BaseRotationConfig subclasses).
algorithm: str = Field(default="hadamard", frozen=True)

# ---- shared ----
backend: str = Field(default="auto")
block_size: Optional[int] = Field(default=None)
hadamard_type: str = Field(default="hadamard")

# ---- inplace-only ----
fuse_online_to_weight: Optional[bool] = Field(default=None)
allow_online_rotation: bool = Field(default=True)

# for random hadamard (transform path)
random_seed: bool = Field(default=False, exclude=True)

model_config = {"arbitrary_types_allowed": True}

def __init__(self, **data: Any) -> None:

Motivation and Use Case

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Alternatives Considered

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Definition of Done

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Additional Context

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[wenhuach21]

@field_validator("backend")
@classmethod
def _validate_backend(cls, v: str) -> str:
    if v not in _SUPPORTED_BACKENDS:
        raise ValueError(f"Unsupported backend: {v}. Supported values: {sorted(_SUPPORTED_BACKENDS)}")
    return v

@field_validator("hadamard_type")
@classmethod
def _validate_hadamard_type(cls, v: str) -> str:
    if v not in HADAMARD_TYPES:
        raise ValueError(f"Unsupported hadamard_type: {v!r}. Supported values: {sorted(HADAMARD_TYPES)}")
    return v