feat(sentry): integrate Sentry SDK with Next.js and configure DSN

- Added Sentry client, server, and edge configurations for enhanced error monitoring.
- Updated `.env.example` and `docker-compose` to include `NEXT_PUBLIC_SENTRY_DSN`.
- Modified `next.config.ts` to use `withSentryConfig` for source map uploads.
- Installed `@sentry/nextjs` as a dependency and updated `pnpm-lock.yaml`.

frontend/sentry.client.config.ts

@@ -0,0 +1,22 @@
+import * as Sentry from "@sentry/nextjs";
+
+Sentry.init({
+  dsn: process.env.NEXT_PUBLIC_SENTRY_DSN,
+  
+  // Ajustez ces valeurs en production
+  tracesSampleRate: 1.0,
+  
+  // Replay est activé par défaut
+  replaysSessionSampleRate: 0.1,
+  replaysOnErrorSampleRate: 1.0,
+
+  integrations: [
+    Sentry.replayIntegration({
+      maskAllText: true,
+      blockAllMedia: true,
+    }),
+  ],
+
+  // Protection PII
+  sendDefaultPii: false,
+});