🔧(frontend) add conditional sourcemap generation for error tracking

Enable sourcemaps via env variable to link Sentry/PostHog exceptions to
source code. Enable by default for DINUM frontend image to improve
debugging capabilities.

docker/dinum-frontend/Dockerfile

@@ -17,6 +17,7 @@ FROM frontend-deps AS meet-builder
 WORKDIR /home/frontend
 
 ENV VITE_APP_TITLE="Visio"
+ENV VITE_BUILD_SOURCEMAP="true"
 
 RUN npm run build