fix(infra): docker-compose.local self-seeds zaaktype, DMN + NRC abonnement (closes #110) (#114)

## What & why

The host-browser stack (`make local`) had drifted behind three slices, so a fresh bring-up couldn't complete the flow: registrations stuck at `OpenZaakAanmaken`, the behandel werkbak stayed empty, and the openbaar register showed nothing. The `verify-*` scripts do this setup for CI at test time; `make local` had no equivalent.

This makes the local stack **self-seed at bring-up** so it just works in a browser:

- **DMN** — `flowable-init` now also deploys `diploma-eligibility.dmn` (was BPMN-only), so completing `WachtOpDocumenten` routes through the DMN to `Beoordelen` instead of 404ing.
- **Zaaktype + ACL** — a `local-seed` one-shot publishes the BIG zaaktype (whose UUID is server-assigned, hence not static in the compose file) and writes the real URLs to `seed-env:/acl.env`; the ACL sources it on startup via an entrypoint override.
- **NRC abonnement** — an `nrc-subscribe` one-shot registers the `zaken` subscription at the event-subscriber callback, so notifications reach the projection/openbaar register.

Both one-shots reach OpenZaak/NRC by **container IP** (a single-label host fails their Django URLValidator), mirroring the CI verify scripts. Design + trade-offs in **ADR-0020**.

Closes #110

## Definition of Done

- [x] Linked Gitea issue (#110).
- [x] Failing test committed before the implementation — `test(infra): …` adds `infra/run-local-flow-check.sh` / `make verify-local`; the three gaps' failures were observed live on a fresh `make local` (red), and the fix turns it green.
- [x] Implementation makes the test pass; docs commit follows.
- [x] Conventional Commits referencing the issue (`refs #110`).
- [ ] CI green — running on the restored runner. Infra-only change; the CI `verify-stack` job uses `docker-compose.yml` (untouched). Also validated locally: `make verify-local` passes against a fresh `make local` (see below).
- [x] `docker compose up` from a fresh clone reaches green health checks — verified: `make local` healthy in ~2m20s, then `make verify-local` green.
- [x] Docs updated — ADR-0020 + demo-script note.
- [x] ADR added in `docs/architecture/` — ADR-0020.
- [x] Demo note in `docs/demo-script.md`.

## Notes for reviewers

- **Infra-only** — no service code changes; the ACL image and the CI stack (`docker-compose.yml`) are untouched.
- **Verified end-to-end on a fresh stack** (`make local-down && make local && make verify-local`):
  ```
  >> 2. zaak opened            (zaaktype seeded + wired)
  >> 3. documents accepted 204 (DMN deployed)
  >> 4. in the werkbak         (DMN routing → Beoordelen)
  >> 5. visible in the openbaar register (NRC abonnement)
  OK — a fresh local stack completed the flow with no manual seeding
  ```
- **Follow-up:** the cleaner design — ACL resolving its zaaktype by `identificatie` instead of a pinned server-assigned URL — is split out as **S-27 (#113)**; landing it would remove the `acl.env` injection here. ADR-0020 records this.
- The `seed-env` volume carries the generated `acl.env` from `local-seed` to the ACL; a `down --volumes` (as `make local-down` does) resets it cleanly.

Reviewed-on: #114

infra/local/seed-zaaktype.sh

@@ -0,0 +1,35 @@
+#!/bin/sh
+# Local-stack bootstrap (S-B04, #110, ADR-0020) — the "seed zaaktype + wire the ACL" step.
+#
+# Runs as the `local-seed` init container of infra/docker-compose.local.yml. It seeds + publishes
+# the BIG zaaktype (and the Diploma informatieobjecttype) into OpenZaak, then writes the resulting
+# **server-assigned** URLs into /out/acl.env, which the ACL entrypoint sources before starting. This
+# is the local-stack equivalent of what infra/run-domain-check.sh does for CI: the zaaktype UUID is
+# assigned by OpenZaak at creation, so it can't be a static value in the compose file.
+#
+# Why the container IP and not the `openzaak` service name: OpenZaak validates URL query params
+# (e.g. ?catalogus=) with Django's URLValidator, which rejects a single-label host like `openzaak`.
+# Seeding against the resolved IP keeps the seeded URLs valid AND host-consistent with the ACL, which
+# we point at the same IP below. See docs/runbooks/gitea-actions-gotchas.md and ADR-0020.
+set -eu
+
+oz_ip="$(python3 -c "import socket;print(socket.gethostbyname('openzaak'))")"
+OZ_BASE="http://${oz_ip}:8000"
+export OZ_BASE OZ_PUBLISH=1
+
+echo ">> seeding + publishing the BIG zaaktype at ${OZ_BASE} (idempotent)"
+out="$(python3 /work/seed_catalogus.py)"
+echo "$out"
+
+zt="$(printf '%s\n' "$out" | sed -n 's/^ZAAKTYPE_URL //p' | head -1)"
+iot="$(printf '%s\n' "$out" | sed -n 's/^INFORMATIEOBJECTTYPE_URL //p' | head -1)"
+[ -n "$zt" ] || { echo "ERROR: seed did not report a ZAAKTYPE_URL" >&2; exit 1; }
+[ -n "$iot" ] || { echo "ERROR: seed did not report an INFORMATIEOBJECTTYPE_URL" >&2; exit 1; }
+
+# The ACL entrypoint sources this; these keys override the placeholder defaults in the compose file.
+cat > /out/acl.env <<EOF
+Acl__OpenZaak__BaseUrl=${OZ_BASE}/
+Acl__Defaults__ZaaktypeUrl=${zt}
+Acl__Defaults__InformatieobjecttypeUrl=${iot}
+EOF
+echo ">> wrote /out/acl.env (base=${OZ_BASE}/ zaaktype=${zt})"