[Bug]: Project icon is missing from the thread header when a project has a second checkout#31305

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

1. Add a project, for example ~/src/myrepo, and give it a custom icon in Project settings (I used a Lucide icon).
2. Later, add a second checkout of the same repository, for example ~/myrepo. The sidebar groups the two under one entry, which still shows the custom icon.
3. Start a new thread in that group so the draft lands in the second checkout.
4. Look at the chat header breadcrumb.

Expected behavior

The breadcrumb shows the project's custom icon, the same one the sidebar group shows.

Actual behavior

The breadcrumb shows the automatic monogram ("SS" for a project called SlopSubs), because the second checkout has no icon of its own.

The icon was saved only on the checkout that existed at the time. The second checkout was created with projectIcon: null. Later group edits write only the changed field to each member: a rename reached both checkouts, but the icon never did. The two views then read different sources:

• The sidebar group takes its icon from its representative member (apps/web/src/sidebarProjectGrouping.ts, buildSidebarProjectSnapshots).
• The chat header reads the thread's own project (useProject(activeProjectRef) in ChatView.tsx, rendered by ProjectFavicon in ChatHeader.tsx).

Other views that show a single project's icon, such as sidebar thread rows and command palette subtitles, probably show the same mismatch. I haven't checked them.

Possible fixes: copy the group's icon (and title) to a checkout when it joins an existing group, or have single-project views use the group's identity. The first fixes the data at its source, but projects that are already out of sync stay that way until their icon is saved again.

Impact

Cosmetic issue. Nothing breaks: threads run normally, and only the icon is wrong.

Version or commit

main @ 67eebaca23

Workaround

Open Project settings for the group and save the icon again. The group update writes it to every checkout.