[Feat/UX Bug] _id and other columns width in aggregator tab is very small

<img width="1652" height="837" alt="Image" src="https://github.com/user-attachments/assets/70264b16-3ec6-4e2d-9de1-49075158ff92" />

The size of the `_id` and any projected column in the Aggregator tab is so small and not customisable. I always have to copy the result to another IDE or export it as CSV to view the data.

**Feature request**

Make the column resizable.