Pair skills and user messages

We could improve upon that... seeing the skill content as a user message (right aligned) breaks the "flow".

<img width="1302" height="516" alt="Image" src="https://github.com/user-attachments/assets/c893faab-00e1-442b-aa0f-7eeadffe15b5" />

Better embed the skill content in the skill tool result.