[Fi-zzy]

Summary

• Wrap the full marketplace listings component on /trades in the existing ErrorBoundary so render failures in filters or page state are caught as well as grid failures.
• Use the existing user-safe retry fallback and monitoring context.
• Add a route-level test that forces a render failure and verifies the fallback is shown.

Validation

• npm test -- --runInBand app/trades/page.test.tsx — passed.
• git diff --check and full added-line PolinRider scan — passed.
• The frontend-wide TypeScript check has pre-existing errors in unrelated metadata, formatting, and config files.

Closes #459