fix(backtest): run and settle a ticker or date given twice once (#1415)

- run_backtest drops repeated tickers and dates before building the grid

tests/test_backtest.py

@@ -296,3 +296,11 @@ def test_a_resumed_sweep_reports_only_the_cells_it_runs(tmp_path):
                  progress=lambda done, total, ticker, date: seen.append((done, total, date)))
 
     assert seen == [(1, 1, "2026-01-12")]
+
+
+@pytest.mark.unit
+def test_a_ticker_or_date_given_twice_runs_and_settles_once(tmp_path):
+    run_backtest(["NVDA", "NVDA"], ["2026-01-05", "2026-01-05"], _config(tmp_path))
+    graph = _FakeGraph.instances[-1]
+    assert graph.calls == [("NVDA", "2026-01-05")]
+    assert graph.settled == ["NVDA"]

tradingagents/backtest.py

@@ -155,6 +155,8 @@ def run_backtest(
     result = BacktestResult(run_id=run_id, log_path=Path(run_config["memory_log_path"]))
     done = {(e["ticker"], e["date"]) for e in graph.memory_log.load_entries()}
 
+    # A ticker or date given twice is one cell, run and settled once.
+    tickers, dates = list(dict.fromkeys(tickers)), list(dict.fromkeys(dates))
     cells = [(ticker, date) for ticker in tickers for date in dates]
     todo = [cell for cell in cells if cell not in done]
     result.skipped = len(cells) - len(todo)