fix: v2.7.1 — the UI builds again (v2.7.0's update failed at npm run build)

- v2.7.0 could not be installed or updated to: the client build
  (`tsc -b && vite build`) type-checks test files too, and a new
  RunSetup test rendered PromptEditor without its required `slash` and
  `fileCwd` props, so `tsc -b` failed and every update stopped at
  "npm run build failed". The test now passes them.
- Verified on a clean v2.7.0 worktree + this fix: `tsc -b` and
  `vite build` both exit 0; RunSetup tests 19/19.

client/src/pages/__tests__/__snapshots__/screens.snapshot.test.tsx.snap

@@ -7174,7 +7174,7 @@ exports[`screen snapshots > Settings — about 1`] = `
                 <span
                   class="text-status-warning/90"
                 >
-                  UI build v2.7.0 (rebuild client to match)
+                  UI build v2.7.1 (rebuild client to match)
                 </span>
               </p>
             </div>