"""
HHD subsystem package.

This package is intended to hold the refactored implementation currently living in
`orisys.HHD`. The old monolithic file can remain as a compatibility layer while code
is moved here gradually.

Suggested migration target:
- `api.py`     -> public `nHHD` class
- `grid.py`    -> `StructuredGrid`
- `poisson.py` -> `PoissonSolver`
- `timing.py`  -> `Timer`
- `kernels.py` -> helper kernels / backend-specific math
"""
from .api import nHHD
from .grid import StructuredGrid
from .poisson import PoissonSolver
from .timing import Timer

__all__ = ["nHHD", "StructuredGrid", "PoissonSolver", "Timer"]
