test: preserve batched context ties and duplicate hits

tests/test_session_search_context_batch.py

@@ -25,3 +25,20 @@ def test_search_context_batches_hits_without_cross_session_neighbors(tmp_path):
         projected = db.search_messages("needleprobe", fields=["id"], limit=20)
         assert len(projected) == len(rows)
         assert not any("WITH target AS" in q for q in sql)
+
+
+def test_context_batches_keep_tied_timestamp_order_and_duplicate_hits(tmp_path):
+    with SessionDB(db_path=tmp_path / "ties.db") as db:
+        db.create_session("ties", "cli")
+        db.append_messages_batch("ties", [
+            {"role": "user", "content": f"needleprobe {i}", "timestamp": 10.0}
+            for i in range(502)
+        ])
+        rows = db.search_messages("needleprobe", limit=502)
+        assert len(rows) == 502
+        by_id = sorted(rows, key=lambda row: row["id"])
+        for i, row in enumerate(by_id):
+            expected = [f"needleprobe {j}" for j in range(max(0, i - 1), min(502, i + 2))]
+            assert [r["content"] for r in row["context"]] == expected
+        duplicate = db._finalize_search_matches([dict(by_id[250]), dict(by_id[250])])
+        assert duplicate[0]["context"] == duplicate[1]["context"] == by_id[250]["context"]