profile: replace default bash prompt with more informative one

profile: replace default bash prompt with more informative one

The default bash PS1 provides mostly no information.
Let's replace it.

Before:
```
[watanabe@thinkpad-x280:~] $ run0
🦸 bash-5.2# echo $PS1
🦸 \s-\v\$
```

After:
```
[watanabe@thinkpad-x280:~] $ run0
🦸 [root@thinkpad-x280 watanabe]# echo $PS1
🦸 [\u@\h \W]\$
```

Fixes #38494.