Create `src/environments/environment.ts` holding the two SPA
per-environment values referenced by ADR-0018: `bffApiBaseUrl`
(default `http://localhost:3000/api`) and `otlpEndpoint` (default
`http://localhost:4318/v1/traces`). The dev defaults match the
current local Docker compose stack — `nx serve portal-shell` keeps
working unchanged.
Replace the hard-coded URLs at the two call sites:
- `observability/tracing.ts` reads `environment.otlpEndpoint` for the
OTLP exporter, and derives the `propagateTraceHeaderCorsUrls`
regex from `environment.bffApiBaseUrl` — a future deploy-time
change to the BFF origin propagates `traceparent` to the right
place automatically.
- `home-status.service.ts` builds the `/health` URL as
`${environment.bffApiBaseUrl}/health`.
Per-environment siblings (`environment.staging.ts`,
`environment.prod.ts`) and the `fileReplacements` configuration in
`project.json` land later — explicitly out of scope today per the
ADR ("ship later"); their values are not known yet and dropping
plausible-but-wrong production URLs into the repo would be worse
than waiting for the infrastructure ADR.