* UOp.param accepts single sint as shape (int,)
Change UOp.param signature from shape:tuple[sint, ...]|None to shape:tuple[sint, ...]|sint|None.
A single sint means 1D shape (sint,). Update all callers from (n,) to n syntax.
No param_from_shape — multi-dim shapes stay as tuples.
* use single int syntax in hcq2 copy_with_kernel