Remove diff renderer lab route

ui/src/App.tsx

@@ -17,7 +17,6 @@ import { Issues } from "./pages/Issues";
 import { Search } from "./pages/Search";
 import { IssueDetail } from "./pages/IssueDetail";
 import { IssueChatLongThreadPerf } from "./pages/IssueChatLongThreadPerf";
-import { RunTranscriptUxLab } from "./pages/RunTranscriptUxLab";
 import { Routines } from "./pages/Routines";
 import { RoutineDetail } from "./pages/RoutineDetail";
 import { UserProfile } from "./pages/UserProfile";
@@ -108,10 +107,7 @@ function boardRoutes() {
       <Route path="issues/recent" element={<Navigate to="/issues" replace />} />
       <Route path="issues/:issueId" element={<IssueDetail />} />
       {import.meta.env.DEV ? (
-        <>
-          <Route path="tests/perf/long-thread" element={<IssueChatLongThreadPerf />} />
-          <Route path="tests/ux/diff-renderer" element={<RunTranscriptUxLab />} />
-        </>
+        <Route path="tests/perf/long-thread" element={<IssueChatLongThreadPerf />} />
       ) : null}
       <Route path="routines" element={<Routines />} />
       <Route path="routines/:routineId" element={<RoutineDetail />} />
@@ -280,7 +276,6 @@ export function App() {
         <Route path="cli-auth/:id" element={<CliAuthPage />} />
         <Route path="invite/:token" element={<InviteLandingPage />} />
         <Route path="tests/perf/long-thread" element={<IssueChatLongThreadPerf />} />
-        <Route path="tests/ux/diff-renderer" element={<RunTranscriptUxLab />} />
 
         <Route element={<CloudAccessGate />}>
           <Route index element={<CompanyRootRedirect />} />