fix(app): show empty review state for projects without VCS - #50265

Closes #49260

Opening Review in a project without VCS spins on "Loading changes…" forever.

Before	After

Why it hangs

flowchart LR
  A["project.vcs === undefined"] --> B["vcsQuery enabled: false"]
  B --> C["TanStack: no fetch, status stays 'pending'"]
  C --> D["ready() = !vcsQuery.isPending = false"]
  D --> E["ReviewEmpty: loading() wins forever"]

• @tanstack/[email protected] getDefaultState → status: 'pending' with no data; shouldLoadOnMount returns false when disabled, so it never leaves that state.
• mode() defaults to "git", and options never includes "turn", so the existing noGit branch (mode() === "turn" && noGit()) was unreachable dead code.

Change

packages/app/src/session/review/model.ts

const ready = () => {
  const project = input.session.project()
  if (project && !project.vcs) return true
  if (mode() === "git" || mode() === "branch") return !vcsQuery.isPending
  return true
}

packages/app/src/session/review/view.tsx

-const noGit = () => props.review.mode() === "turn" && props.review.noGit()
+const noGit = () => props.review.noGit()

• Any truthy project.vcs (git or another backend) keeps the current loading behaviour, matching fix(app): show review diffs for non-git VCS backends #46684.
• Unknown project (undefined) still shows loading until the project resolves.
• The already-localised session.review.noVcs.createGit.* empty state renders instead of the misleading "No uncommitted changes yet".