Search chat history

[Moshyfawn]

Summary: Add the ability to search the chat history in Zed.

Probably another one of those more "management" items, but I go into why I think these are valid in my eyes in #10135.

This is more of a community management type request, but as Zed is more than an IDE and strives to be a collaboration platform, there's a fair chance there will be more use cases where communities would like to see moderation tools and better chat management support UX.

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I would like to be able to search the chat history.

[maxdeviant]

I think this will make sense to pick up once we visit the chat functionality. Going to move to a discussion, in the meantime.