fix(driver): show invalid route upload errors on upload page

[hir-al-14]

Summary

• Invalid route uploads now show a clear error on /upload-route instead of sending drivers to the deprecated driver_assist tester upload screen.
• The old in-page Driver Assist JSON upload fallback has been removed.

Motivation

• Drivers should see upload failures on the page where they selected the route file so they can retry immediately.
• Before this change, invalid JSON or invalid route-shaped JSON was only detected after navigating to /driver_assist, which exposed an old unstyled fallback upload UI.

Changes

• Frontend:

  • Added shared /upload-route validation that parses and transforms route uploads before navigating.
  • Stores invalid upload errors in session storage and renders them in the existing /upload-route error block.
  • Redirects Driver Assist import failures back to /upload-route instead of rendering the deprecated fallback screen.
  • Removed the deprecated Driver Assist direct-upload fallback path, unused file input state, import handler, and related styles.
  • Added regression coverage for rejecting invalid upload-route files before handing them to Driver Assist.

• Backend: No backend changes.

Validation

Frontend

• npm.cmd --prefix app/ui run lint
• npm.cmd --prefix app/ui run format:check
• npm.cmd --prefix app/ui run typecheck
• npm.cmd --prefix app/ui run test
• npm.cmd --prefix app/ui run build
• npm.cmd --prefix app/mobile run lint
• npm.cmd --prefix app/mobile run typecheck

Backend

• cmake --preset dev
• .github/scripts/check-backend-static.sh build/dev
• cmake --build --preset dev --parallel
• ctest --preset dev --output-on-failure --no-tests=error -LE 'e2e|docker'

Risk

• Main behavior change is limited to the Driver Assist route upload/import flow.
• Valid route files still import and navigate to /driver_assist.
• Invalid files now stop on /upload-route with the existing styled error UI.

Rollout and Recovery

• Roll out normally with the frontend deploy.
• If anything looks wrong, revert this PR to restore the previous Driver Assist import behavior.

High-Signal PR Checklist

• The summary states the user-visible or operational outcome, not just file names.
• The motivation explains why this change is needed now.
• The change list separates frontend, backend, infrastructure, and documentation work where applicable.
• Validation includes exact commands run, relevant output, and any checks intentionally skipped.
• Risks, migrations, feature flags, and rollback steps are called out when relevant.
• Screenshots or request/response examples are included for UI and API behavior changes.

Related Issues

#198

• The deprecated in-page tester upload screen in Driver Assist is removed.
• Uploading an invalid route file via /upload-route shows an error on /upload-route.
• Valid route files still import and navigate to /driver_assist.
• Dead code from the removed fallback path is removed.
• Regression test added for the invalid upload-route error path.

[markboenigk]

Overall: Clean direction — removing the deprecated upload screen from /driver_assist and surfacing errors on /upload-route is the right call. A few things worth fixing before merge.

Bug — sessionStorage.setItem can throw inside a catch block

In driver_assist/page.tsx, the import-error handler does:

} catch (importError) {
  const message = ...;
  clearUploadedRouteFile();
  sessionStorage.setItem(ROUTE_UPLOAD_ERROR_KEY, message); // ← throws in private browsing
  router.replace("/upload-route");
  return;
}

sessionStorage.setItem throws a SecurityError in private-browsing mode (iOS Safari, Firefox strict mode) and a QuotaExceededError if storage is full. Because we're already in a catch, the new exception escapes into React — the redirect never runs and the user is stuck. Wrap the setItem + router.replace in a try/catch, or fall back to a query param if storage is unavailable.

Design — parseRouteUploadText result is discarded; the file is parsed twice

In upload-route/page.tsx:

parseRouteUploadText(text);  // validated and transformed → result thrown away
sessionStorage.setItem("routeFile", JSON.stringify({ name: file.name, content: text }));
router.push("/driver_assist");

Then driver_assist calls loadSessionFromText + transformSessionToDriverRoute on the same string all over again. The two functions are identical in both places, so no behavioral difference today — but this is fragile: any future divergence (extra validation step, schema migration) will silently create inconsistent behavior between pages. Consider storing the already-transformed result in sessionStorage (or at least a comment explaining why re-parsing is intentional).

Nit — ROUTE_UPLOAD_ERROR_KEY belongs in a shared location

driver_assist importing from @/app/upload-route/routeUploadValidation inverts the expected sibling-route boundary. If routeUploadValidation ever gains a transitive import from driver_assist, you have a circular dependency. Moving the constant (and arguably the key itself) to lib/driver-route/ or a shared constants file removes that risk and makes the coupling explicit.

Nit — queueMicrotask wrappers are unnecessary

React 18 batches all setState calls inside useEffect automatically. The queueMicrotask(() => { setRoute(...); setHasCheckedRoute(true); }) pattern in both the success and saved-route branches adds a render-cycle delay and makes the timing harder to reason about without any benefit. Calling the setters directly works identically — same for the queueMicrotask(() => setError(...)) in upload-route/page.tsx.