refactor: make ARNES external-repo based with ticket publish flow

harness/workflow.stages.yml

@@ -63,9 +63,16 @@ stages:
       - work/artifacts/<feature_id>/leader-close.json
       - work/history.md
 
+  - name: publish
+    owner: leader
+    required: true
+    output:
+      - work/artifacts/<feature_id>/publish.json
+
 close_requirements:
   - reviewer.json.verdict == "APPROVED"
   - security.json.verdict == "APPROVED"
   - qa.json.verdict == "APPROVED"
   - documenter.md exists
+  - publish.json.verdict == "PUBLISHED"
   - scripts/verify.sh exit_code == 0