Copilot/setup sentry nextjs (#58)

* Revise portfolio: warm brown theme, elegant typography, optimized analytics tracking (#55)

* Initial plan

* Update color theme to warm brown and off-white, add elegant fonts, fix analytics tracking

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

* Fix 404 page integration with warm theme, update admin console colors, fix font loading

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

* Address code review feedback: fix navigation, add utils, improve tracking

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

* Fix accessibility and memory leak issues from code review

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

* chore: Code cleanup, add Sentry.io monitoring, and documentation (#56)

* Initial plan

* Remove unused code and clean up console statements

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

* Remove unused components and fix type issues

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

* Wrap console.warn in development check

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

* Integrate Sentry.io monitoring and add text editing documentation

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

* Initial plan

* feat: Add Sentry configuration files and example pages

- Add sentry.server.config.ts and sentry.edge.config.ts
- Update instrumentation.ts with onRequestError export
- Update instrumentation-client.ts with onRouterTransitionStart export
- Update global-error.tsx to capture exceptions with Sentry
- Create Sentry example page at app/sentry-example-page/page.tsx
- Create Sentry example API route at app/api/sentry-example-api/route.ts

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

* feat: Update middleware to allow Sentry example page and fix deprecated API

- Update middleware to exclude /sentry-example-page from locale routing
- Remove deprecated startTransaction API from Sentry example page
- Use consistent DSN configuration with fallback values

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

* refactor: Improve Sentry configuration with environment-based sampling

- Add comments explaining DSN fallback values
- Use environment-based tracesSampleRate (10% in production, 100% in dev)
- Address code review feedback for production-safe configuration

Co-authored-by: denshooter <44590296+denshooter@users.noreply.github.com>

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Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>

app/privacy-policy/page.tsx

@@ -173,6 +173,32 @@ export default function PrivacyPolicy() {
           Nutzungsstatistiken erfassen (z.B. Seitenaufrufe, Performance-Metriken),
           die erst nach deiner Einwilligung im Consent-Banner aktiviert werden.
         </p>
+
+        <h2 className="text-2xl font-semibold mt-6">Error Monitoring (Sentry)</h2>
+        <p className="mt-2">
+          Um Fehler und Probleme auf dieser Website schnell zu erkennen und zu beheben, 
+          nutze ich Sentry.io, einen Dienst zur Fehlerüberwachung. Dabei werden technische 
+          Informationen wie Browser-Typ, Betriebssystem, URL der aufgerufenen Seite und 
+          Fehlermeldungen an Sentry übermittelt. Diese Daten dienen ausschließlich der 
+          Verbesserung der Website-Stabilität und werden nicht für andere Zwecke verwendet.
+          <br />
+          <br />
+          Anbieter: Functional Software, Inc. (Sentry), 45 Fremont Street, 8th Floor, 
+          San Francisco, CA 94105, USA
+          <br />
+          <br />
+          Rechtsgrundlage: Art. 6 Abs. 1 S. 1 lit. f DSGVO (berechtigtes Interesse an 
+          der Fehleranalyse und Systemstabilität).
+          <br />
+          <br />
+          Weitere Informationen: <Link
+            className="text-blue-700 transition-underline"
+            href={"https://sentry.io/privacy/"}
+          >
+            Sentry Datenschutzerklärung
+          </Link>
+        </p>
+
         <h2 className="text-2xl font-semibold mt-6">Kontaktformular</h2>
         <p className="mt-2">
           Wenn Sie das Kontaktformular nutzen, werden Ihre Angaben zur