sidebar: Add a new thread draft system (#53574)

Release Notes:

- N/A

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Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>
Co-authored-by: Nathan Sobo <nathan@zed.dev>
86f55495c2Danilo Leal committed on 4/10/2026, 11:19:55 PM· committed by GitHubparentf447724
7 files changedLine totals unavailable