feat(sentry): Polish demo page design & fix server instrumentation DSN loading (#239)

* Update Sentry example page design

* checksum?

Author: HazAT

frameworks/react-cra/add-ons/sentry/assets/instrument.server.mjs

@@ -4,4 +4,7 @@ Sentry.init({
   // Adds request headers and IP for users, for more info visit:
   // https://docs.sentry.io/platforms/javascript/guides/tanstackstart-react/configuration/options/#sendDefaultPii
   sendDefaultPii: true,
+  tracesSampleRate: 1.0,
+  replaysSessionSampleRate: 1.0,
+  replaysOnErrorSampleRate: 1.0,
 })