fix(harness): record postgres decision phases

harness/tests/test_postgres_session_repository.py

@@ -6,6 +6,7 @@ from sqlalchemy import create_engine, text
 from testcontainers.postgres import PostgresContainer
 
 from tht.decisions import DecisionInput
+from tht.phase import effective_decisions
 from tht.session.models import PrincipalContext, SessionManifest
 from tht.session.store import SessionError
 
@@ -61,6 +62,27 @@ def test_owner_can_read_own_snapshot_but_not_another_owners(database_url):
         bob.get(session_id)
 
 
+def test_named_decision_is_stale_after_postgres_ledger_reopen(database_url):
+    repository = _repository(database_url, "phase-owner")
+    session_id = str(uuid.uuid4())
+    repository.create(_manifest(session_id))
+    for phase in range(1, 5):
+        repository.append_decisions(session_id, [
+            DecisionInput(type="phase_approved", subject=f"phase:{phase}")
+        ])
+    repository.append_decisions(session_id, [
+        DecisionInput(type="cte_approved", subject="named_cte")
+    ])
+    repository.append_decisions(session_id, [
+        DecisionInput(type="phase_reopened", subject="phase:3")
+    ])
+
+    snapshot = repository.get(session_id)
+    named = next(item for item in snapshot.decisions if item.subject == "named_cte")
+    assert named.phase == 5
+    assert "named_cte" not in {item.subject for item in effective_decisions(snapshot)}
+
+
 def test_admin_can_read_another_owners_session(database_url):
     owner = _repository(database_url, "owner")
     admin = _repository(database_url, "admin", is_admin=True)