Make custom elements a first class citizen

[josca42]

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Quickly creating beautiful UI elements in claude and adding them as custom elements in chainlit enables creating beautiful UX flows that differentiate from the just another chat bot experience. A quick example of this is shown in this video .

Claude natively uses shadcn and recharts so everything almost work out of the box but a few key changes are needed. More tailwind styling needs to be made available to the custom elements. And since a lot of chainlit users will likely be using it related to analysis workflows - preferring chainlit to streamlit etc. - then the charting functionality used by claude should be available. This means recharts and the shadcn chart component.

This also addresses #2328