add preview project block from soup and project block

[aquaductape]

Summary

Screenshots, GIFs, and Videos

[linear]

M-5375 Support folder preview mode

[gbirman]

why are we doing this scoping? all the other previews don't use this

[aquaductape]

Without scoping, causes infinite loop where root project Block keeps switching between initial project view and project rendered inside preview due to Project Block's updating root context in createEffect+onCleanup logic. With scoping, it only updates the context created inside PreviewPanel not the root split panel context.

createRenderEffect(() => {
  const previousView = untrack(selectedView);
  setSelectedView(projectId); 
  // ...

  onCleanup(() => {
    setSelectedView(previousView);
    setViewDataStore(projectId, undefined);
  });
});

Plus scoping scopes the hotkeys to the Project Block rendered inside PreviewPanel, so when PreviewPanel is focused, jk is navigates entities inside of preview instead of root Block.

[gbirman]

@aquaductape taking a look now

[gbirman]

issues:

• duplicate share buttons ( see below). this messed up tool bar exists for all previewed files/folders in project block because the share button will occupy full width but the filter/display buttons are only over the unified list view + we have two competing top bars. im not sure what ppl want from the ui exactly but can u sync with @synoet for what we should be doing because it's too jank atm

• can't click into project that's previewed. yes it's previewed but i may still want to open it completely. I guess this is general preview behavior so can be done in a follow up ticket: https://macro.com/app/channel/0195ceb6-ec2e-7023-80e4-6e084fa6cccd?message_id=019b0e36-c8e6-72cc-904f-16dbd09cabf2
• once preview project steals focus its very unintuitive/difficult to get the folders list back in focus so the j/k hotkeys work. like if i click back on the selected project it doesnt return focus