Accept non-UUID triggering_event_id and add GitOps runbook

Broaden POST /issues/ so triggering_event_id is any non-empty traceability
string, enabling cron/scheduled activity-core emissions with stable keys like
"scheduled" while event-driven paths still send UUIDs. Document the railiance01
ArgoCD deployment path in docs/argocd-gitops.md and update ISSUE-WP-0003 task
status to reflect repo-side progress.

tests/test_api_ingest.py

@@ -112,6 +112,30 @@ def test_ingest_creates_issue_with_x_api_key(client, valid_payload):
     assert response.status_code == 201, response.text
 
 
+@pytest.mark.unit
+def test_ingest_accepts_non_uuid_triggering_event_id(client, valid_payload, tmp_issue_store):
+    valid_payload["triggering_event_id"] = "scheduled"
+    response = client.post(
+        "/issues/",
+        json=valid_payload,
+        headers={"Authorization": f"Bearer {API_KEY}"},
+    )
+    assert response.status_code == 201, response.text
+    issue_id = response.json()["issue_id"]
+
+    from issue_core.backends.local import LocalSQLiteBackend
+
+    backend = LocalSQLiteBackend()
+    backend.connect({"type": "local", "db_path": str(tmp_issue_store / "issues.db")})
+    try:
+        stored = backend.get_issue(issue_id)
+        assert stored is not None
+        ingestion = stored.sync_metadata.get("ingestion") or {}
+        assert ingestion["triggering_event_id"] == "scheduled"
+    finally:
+        backend.disconnect()
+
+
 @pytest.mark.unit
 def test_ingest_rejects_invalid_payload(client):
     bad = {"title": "no required fields"}