refactor(harness): route workflow persistence through repositories

harness/tests/test_require_phase_or_exit.py

@@ -16,8 +16,13 @@ def _make_session(tmp_path, current_phase_num: int) -> str:
     approving phases 1..N-1 puts the session at phase N."""
     import json
 
-    s = tmp_path / "sess"
+    session_id = "2026-07-16-120000"
+    s = tmp_path / session_id
     s.mkdir()
+    (s / "session_manifest.yaml").write_text(
+        f"id: {session_id}\nquestion: q\ndatabase: d\nschema: s\n"
+        "created_at: 2026-01-01T00:00:00+00:00\nstatus: open\n"
+    )
     decisions = [
         {"seq": n, "type": "phase_approved", "subject": f"phase:{n}", "ts": "2025-01-01T00:00:00"}
         for n in range(1, current_phase_num)
@@ -25,7 +30,7 @@ def _make_session(tmp_path, current_phase_num: int) -> str:
     (s / "review_decisions.jsonl").write_text(
         "\n".join(json.dumps(d) for d in decisions) + ("\n" if decisions else "")
     )
-    return "sess"
+    return session_id
 
 
 class _StubConfig: