webui: add model information dialog to router mode (#20600)
* webui: add model information dialog to router mode
* webui: add "Available models" section header in model list
* webui: remove nested scrollbar from chat template in model info dialog
* chore: update webui build output
* feat: UI improvements
* refactor: Cleaner rendering + UI docs
* chore: update webui build output
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Co-authored-by: Aleksander Grygier <aleksander.grygier@gmail.com>
