[playground] Config panel quality fixes

[EugeneChoi4]

Fixed two small issues with the config panel in the compiler playground:

1. Object descriptions were being confined in the config box and most of it would not be visible upon hover
2. Changed it so that "Applied Configs" would only display a valid set of configs, rather than switching between "Invalid Configs" and the set of options. This would be less visually jarring for users as the Output panel already displays errors. Additionally, if users want to see the list of config options but have a currently broken config, they would previously not know how to fix it.

Object hover before:

Hover after:

Applied Configs always displays the last valid set of configs:

Screen.Recording.2025-09-26.at.11.39.09.AM.mov