Improving the header

# Issues

- Header items require a better layouting to harness the space used.
- And colors of Rainbow Wallet buttons should have a good constrast for different avatar colors.

<img width="1740" height="93" alt="Image" src="https://github.com/user-attachments/assets/e8a11e05-fb6e-46bd-928d-b4dc83499ab6" />
