Add PostHog CLI step to inject proper IDs into chunks, enabling error
tracking to map exceptions back to original source code locations
via sourcemaps.
Enable sourcemaps via env variable to link Sentry/PostHog exceptions to
source code. Enable by default for DINUM frontend image to improve
debugging capabilities.
Create DINUM-specific frontend build from generic white-label base to
validate recent white-labeling work. Sources will eventually be extracted
to separate repo and pulled as submodule.
