chore: remove Sentry verification error from frontend

The test error was firing on every production page load — no longer needed
now that Sentry is confirmed working.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/instrument.ts

@@ -28,9 +28,4 @@ Sentry.init({
   // 1% of normal sessions, 100% of error sessions
   replaysSessionSampleRate: import.meta.env.PROD ? 0.01 : 0.0,
   replaysOnErrorSampleRate: 1.0,
-});
-
-// TODO: Remove after verifying Sentry is receiving frontend events
-if (import.meta.env.PROD) {
-  Sentry.captureException(new Error("ResolutionFlow frontend Sentry verification"));
-}
+});