fix(workflow): use a DMN service task, not businessRuleTask (S-13, refs #14)

flowable-rest's businessRuleTask parse handler binds the legacy Drools/KIE
implementation (NoClassDefFoundError: org.kie.api...AgendaFilter at deploy time),
so registratie.bpmn failed to deploy and flowable-init exited 22. Flowable's
supported inline-DMN construct is a serviceTask with flowable:type="dmn" — switch
to it. The DMN cross-deploy via the process repository (previous commit) was fine;
this was the BPMN parse. Docs/comments updated to match.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

infra/run-domain-check.sh

@@ -159,7 +159,7 @@ done
 echo "OK — withdrawal cancelled the Beoordelen task; the registratie process ended (ingetrokken)"
 
 # ── S-13: diploma-eligibility routing. A registration with a FOREIGN diploma must route through the
-# extra CBGVAdvies user task before Beoordelen (the DMN businessRuleTask sets route=CBGV_ADVIES and the
+# extra CBGVAdvies user task before Beoordelen (the DMN service task sets route=CBGV_ADVIES and the
 # gateway branches, ADR-0016). The domestic DIRECT path is already proven by the first registration
 # above, which parked straight at Beoordelen. ──────────────────────────────────────────────────────
 cbgv_query='{"processDefinitionKey":"registratie","taskDefinitionKey":"CBGVAdvies","includeProcessVariables":true}'