`logcosh(x)` accuracy vanishes around the zero, at `x = 0`

The error in ULPs (here for `logcosh(x::Float64)`) has a spike around `x = 0`:

<img width="1492" height="484" alt="Image" src="https://github.com/user-attachments/assets/f9f95dcb-241f-455f-be68-18d4c19b84d7" />

The right base of the spike:

<img width="1484" height="481" alt="Image" src="https://github.com/user-attachments/assets/1b6aaa4c-163e-4f8e-bb0e-7901f976e26e" />