Add comprehensive error boundary for each route section

[Wilfred007]

What

Some routes lack ErrorBoundary wrappers. When components crash, the entire app goes white. Ensure every route has an ErrorBoundary with a meaningful fallback.

Why

A single component error shouldn't crash the whole app. Error boundaries isolate failures to individual routes.

Scope

In scope: Ensure every route has ErrorBoundary, add "Try Again" button to fallbacks, log errors to Sentry
Out of scope: Error reporting service setup

Acceptance Criteria

• Every route wrapped in ErrorBoundary
• Fallback shows error message and "Try Again" button
• Error doesn't propagate to parent routes
• Console shows component stack trace in dev mode

Technical Context

• frontend/src/components/ErrorBoundary.tsx — existing boundary
• frontend/src/components/ErrorFallback.tsx — existing fallback
• frontend/src/App.tsx — route definitions

[waterWang]

I will work on this issue.

[waterWang]

PR submitted: #586