Update spacing on CI variables table

What does this MR do and why?

• Moves attributes into key column to increase horizontal space for each cell
• Updates percentages for better key/value readability
• Use small copy button variant

#423352 (closed)

What does this MR not do?

It's not perfect on smaller screens; all the cards need mobile improvements

Screenshots or screen recordings

	Before	After
Hidden values
Revealed values

How to set up and validate locally

Project > Settings > CI/CD > Variables

UX Paper Cuts 16.4 → Pipelines and Jobs (#408231 - closed)