Fix unreadable user markdown colors and truncate long texts in deletion dialogs ...

Fix unreadable user markdown colors and truncate long texts in deletion dialogs (#17555)

* webui: limit conversation name length in dialogs

* webui: fix unreadable colors on links and table cell hover in user markdown

* webui: keep table borders visible in user markdown

* webui: updating unified exports

* Update tools/server/webui/src/lib/components/app/chat/ChatAttachments/ChatAttachmentThumbnailFile.svelte

Co-authored-by: Aleksander Grygier <redacted>
* chore: update webui build output

* chore: update webui build output

* chore: update webui build output

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Co-authored-by: Aleksander Grygier <redacted>