feat(acl): diploma upload stored in the ZGW Documenten API (S-10b, closes #103) (#108)

## What & why

S-10b: the self-service **diploma upload** is now real. After submitting, the citizen picks a PDF and
uploads it; the portal base64-encodes it client-side → BFF → domain → **ACL**, which stores it in the
ZGW **Documenten (DRC) API** as an `enkelvoudiginformatieobject` and relates it to the zaak, then the
`WachtOpDocumenten` wait completes and the case advances to beoordeling. Per §8.1 only the ACL talks to
ZGW.

Closes #103

Mechanism in **ADR-0018** (proposal #107). Builds on S-10a (#102). The zaak-close-on-expiry item is
carved to **#106 (S-10c)**.

## Definition of Done

- [x] Linked Gitea issue (above).
- [x] Failing test committed before the implementation (red→green per layer).
- [x] Conventional Commits referencing the issue (`refs #103`).
- [ ] CI green — all Gitea Actions jobs (pending on this PR).
- [x] `docker compose up` health unaffected (ACL boots on a placeholder informatieobjecttype URL; the real one is injected by verify-domain).
- [x] Docs updated (ADR-0018, demo-script, BACKLOG + S-10c).
- [x] ADR added (`docs/architecture/adr-0018-diploma-upload-via-acl-documenten.md`).
- [x] Demo note in `docs/demo-script.md`.

## Notes for reviewers

- **ACL** (`OpenZaakGateway.StoreDocumentAsync` + `AclService.StoreDiplomaAsync` + `POST /documenten`) reuses the existing gateway patterns (ZGW Bearer, buffered non-chunked body, **no CRS** — Documenten isn't geo). Unit-tested via the stub handler; an **integration test** stores a real document against live OpenZaak (verify-acl).
- **Transport:** base64 JSON on every hop (portal encodes client-side) — I deviated from proposal #107's multipart to keep one contract shape and avoid `IFormFile`/antiforgery/multipart-client plumbing; fine at diploma size (ADR-0018 §Alternatives).
- **Infra:** `seed_catalogus.py` seeds + publishes a "Diploma" `informatieobjecttype` and relates it to the zaaktype (while both concept); `verify-domain` injects its URL into the ACL. No new ZGW scopes (seed applicatie has `heeft_alle_autorisaties`).
- **e2e:** uploads a real PDF (`setInputFiles`) after the openbaar INGEDIEND row confirms the zaak is open (so storage doesn't race the OpenZaak worker).
- **Scope boundary:** the ZGW zaak is not set to a cancellation status on 30-day expiry — that's #106 (S-10c).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Reviewed-on: #108

infra/openzaak/seed_catalogus.py

@@ -124,6 +124,58 @@ def publish_zaaktype(zt):
         print("skip   publish (already published)")
 
 
+def seed_informatieobjecttype(cat, zt):
+    """Create the "Diploma" informatieobjecttype and relate it to the zaaktype (both idempotent).
+
+    A diploma uploaded in S-10b is filed under this informatieobjecttype; OpenZaak only accepts a
+    document (and its zaak relation) once the informatieobjecttype is published AND allowed for the
+    zaak's zaaktype (a zaaktype-informatieobjecttype relation). Both the relation and this call must run
+    while the zaaktype is still a concept, so seed this *before* publishing the zaaktype. Returns the
+    informatieobjecttype dict.
+    """
+    iots = [i for i in find(f"/informatieobjecttypen?catalogus={cat['url']}&status=alles")
+            if i.get("omschrijving") == "Diploma"]
+    if iots:
+        iot = iots[0]
+        print(f"skip   informatieobjecttype Diploma ({iot['url']}) concept={iot.get('concept')}")
+    else:
+        st, iot = api("POST", "/informatieobjecttypen", {
+            "catalogus": cat["url"],
+            "omschrijving": "Diploma",
+            "vertrouwelijkheidaanduiding": "openbaar",
+            "informatieobjectcategorie": "diploma",
+            "beginGeldigheid": "2026-01-01",
+        })
+        if st != 201:
+            sys.exit(f"create informatieobjecttype -> {st}: {json.dumps(iot, indent=2)}")
+        print(f"create informatieobjecttype Diploma ({iot['url']})")
+
+    # Relate it to the zaaktype (must be done while both are concept).
+    relations = find(f"/zaaktype-informatieobjecttypen?zaaktype={zt['url']}&status=alles")
+    if any(r.get("informatieobjecttype") == iot["url"] for r in relations):
+        print("skip   zaaktype-informatieobjecttype Diploma")
+    else:
+        st, body = api("POST", "/zaaktype-informatieobjecttypen", {
+            "zaaktype": zt["url"], "informatieobjecttype": iot["url"],
+            "volgnummer": 1, "richting": "inkomend"})
+        if st != 201:
+            sys.exit(f"relate zaaktype-informatieobjecttype -> {st}: {json.dumps(body, indent=2)}")
+        print("create zaaktype-informatieobjecttype Diploma")
+
+    return iot
+
+
+def publish_informatieobjecttype(iot):
+    """Publish the informatieobjecttype (idempotent) so documents may reference it."""
+    if iot.get("concept", True):
+        st, body = api("POST", f"{iot['url']}/publish")
+        if st != 200:
+            sys.exit(f"publish informatieobjecttype -> {st}: {json.dumps(body, indent=2)}")
+        print(f"publish informatieobjecttype Diploma ({iot['url']})")
+    else:
+        print("skip   publish informatieobjecttype (already published)")
+
+
 def main():
     # 1. Catalogus
     existing = [c for c in find(f"/catalogussen?domein=BIG") if c.get("domein") == "BIG"]
@@ -198,10 +250,16 @@ def main():
     # schema-mandatory" zaaktype S-01 asks for (ADR-0002). Set OZ_PUBLISH=1 to add
     # those relations and publish — needed so a real zaak POST is accepted, which
     # the ACL integration test (S-04a, #46) exercises. See ADR-0006.
+    iot = None
     if PUBLISH:
         # Re-fetch: the bsn-eigenschap branch above may hold a stale concept flag.
         zt = next(z for z in find(f"/zaaktypen?catalogus={cat['url']}&status=alles")
                   if z.get("identificatie") == "BIG-REGISTRATIE")
+        # Seed + relate the Diploma informatieobjecttype (S-10b) while the zaaktype is still concept,
+        # then publish both. Publish the informatieobjecttype before the zaaktype so the zaaktype's
+        # relations reference a published type.
+        iot = seed_informatieobjecttype(cat, zt)
+        publish_informatieobjecttype(iot)
         publish_zaaktype(zt)
 
     # 5. Verify the JWT client can list the zaaktype (concepts included).
@@ -214,6 +272,10 @@ def main():
     # zaaktype URL to configure the ACL's default-fill (ADR-0003/0009).
     zt_url = next(z["url"] for z in zaaktypen if z.get("identificatie") == "BIG-REGISTRATIE")
     print(f"ZAAKTYPE_URL {zt_url}")
+    # Machine-readable informatieobjecttype URL (S-10b) so callers can configure the ACL's document
+    # default-fill. Only emitted when publishing — a concept informatieobjecttype can't back a document.
+    if iot is not None:
+        print(f"INFORMATIEOBJECTTYPE_URL {iot['url']}")
     print(f"OK — BIG catalogus seeded (BIG-REGISTRATIE {state} + bsn eigenschap)")