fix(realestate-notifier): preserve threshold=0 and test sent_ids retry path

- Replace `or 70` fallback with explicit None-check so that
  min_match_score=0 ("notify all matches") is no longer silently
  coerced to 70
- Add test: 200 OK + sent_ids=[] must not mark matches notified
- Add test: threshold=0 correctly pushes low-score matches

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

realestate-lab/app/notifier.py

@@ -24,7 +24,8 @@ def notify_new_matches() -> dict:
     if not profile.get("notify_enabled"):
         return {"sent": 0, "skipped": "notify_disabled"}
 
-    threshold = profile.get("min_match_score") or 70
+    raw_threshold = profile.get("min_match_score")
+    threshold = 70 if raw_threshold is None else raw_threshold
     matches = get_unnotified_matches(threshold)
     if not matches:
         return {"sent": 0}

realestate-lab/tests/test_notifier.py

@@ -83,3 +83,42 @@ def test_notify_does_not_mark_on_failure():
     assert row["notified_at"] is None
     assert result["sent"] == 0
     assert "error" in result
+
+
+def test_notify_does_not_mark_when_sent_ids_empty():
+    """agent-office가 200 OK + sent_ids=[]을 반환하면 마킹하지 않고 다음 사이클 재시도 가능."""
+    from app import notifier
+    from app.db import _conn
+
+    match_id = _seed_profile_and_match(score=80, threshold=70)
+
+    fake_resp = MagicMock()
+    fake_resp.json.return_value = {"sent": 0, "sent_ids": []}
+    fake_resp.raise_for_status.return_value = None
+
+    with patch.object(notifier.requests, "post", return_value=fake_resp):
+        result = notifier.notify_new_matches()
+
+    with _conn() as conn:
+        row = conn.execute("SELECT notified_at FROM match_results WHERE id=?", (match_id,)).fetchone()
+
+    assert row["notified_at"] is None
+    assert result["sent"] == 0
+
+
+def test_notify_threshold_zero_pushes_all_matches():
+    """min_match_score=0이면 모든 양수 점수 매치를 알림."""
+    from app import notifier
+    from app.db import _conn
+
+    match_id = _seed_profile_and_match(score=10, threshold=0)
+
+    fake_resp = MagicMock()
+    fake_resp.json.return_value = {"sent": 1, "sent_ids": [match_id]}
+    fake_resp.raise_for_status.return_value = None
+
+    with patch.object(notifier.requests, "post", return_value=fake_resp) as post:
+        result = notifier.notify_new_matches()
+
+    assert post.call_count == 1
+    assert result["sent"] == 1