## What & why
Closes#96. The portal nginx configs hardcode `resolver 127.0.0.11` (Docker's embedded DNS) for their variable `proxy_pass` to the BFF, so on rootless **podman** (network-specific aardvark DNS) every proxied call 502'd — the portals loaded and login worked, but no in-app data flowed.
Add a shared `/docker-entrypoint.d` hook (`apps/portal-nginx-resolver.sh`, wired into all three portal Dockerfiles) that rewrites the resolver from the container's own `/etc/resolv.conf` at startup: a **no-op on Docker** (nameserver *is* 127.0.0.11) and **correct on podman** (rewrites to e.g. 10.89.0.1). nginx.conf is unchanged (the hardcoded value is the substitution anchor).
## How verified
Built the behandel image and ran it on the compose network under podman: the hook rewrote the config to `resolver 10.89.0.1`, and `GET /behandel/werkbak` proxied to the BFF returning **401** (auth), not 502. On Docker the nameserver is 127.0.0.11 so the substitution is a no-op and CI/e2e behaviour is unchanged.
Reviewed-on: #97
## What & why
Before this change the self-service confirmation and the openbaar register showed **different** identifiers, so a citizen could not look their registration back up (#78). Now both surface the same **reference**:
- **domain → ACL (write):** the domain `registrationId` is set as the zaak's `identificatie` on `POST /zaken`.
- **event-subscriber → ACL (read):** the subscriber reads the zaak's `identificatie` back through the ACL (§8.1 — only the ACL talks to ZGW) via a new `POST /zaken/reference`, and stores it on the projection row **and** the `processed_notifications` replay log.
- **BFF + openbaar:** the public view exposes `id/status/reference` (never bsn/naam) and searches by id or reference; the register's "Referentie" column shows the reference.
Storing the reference in the replay log keeps ADR-0008's **rebuild-is-log-only** invariant intact — `/admin/rebuild` reproduces the reference without re-reading the ACL.
Decision recorded in **ADR-0012**.
## Definition of Done
- [x] Linked issue: #78
- [x] Tests written first; red → green per layer
- [x] Unit + acceptance green (`make unit`): domain 49, acl 27, bff 20, event-subscriber 19, acceptance 7
- [x] Frontend lint + test green (`nx run-many -t lint test`)
- [x] Mutation ≥ break(90): acl 100%, event-subscriber 100%, bff 100%, domain 98.41% (pre-existing FlowableWorkflowClient baseline, untouched)
- [x] e2e extended: confirmation reference == register reference
- [x] openapi.json + api-client regenerated (drift guard green)
- [x] ADR-0012 added; demo-script note appended
- [x] `Acl__BaseUrl` wired for the subscriber in compose
closes#78
Reviewed-on: #79
