[dev-overlay] style: make `<a>` tag in Terminal to stand out (#76483)
### Why?
The color of a tag from the CSS reset has a bad color contrast with the
background colors. Also, the hotlink text used in the Terminal component
didn't stand out, which is easy to miss.
https://github.com/vercel/next.js/blob/265aba55ef048537ca5d69702b12c1231ec2d3b3/packages/next/src/client/components/react-dev-overlay/ui/styles/css-reset.tsx#L159-L168
| ------ | Before | After |
|--------|--------|--------|
| Light | 
| 
|
| Dark | 
| 
|
Closes NDX-900
next.js
825246f5 - [dev-overlay] style: make `<a>` tag in Terminal to stand out (#76483)
