feat(b3b): expose candidate-top-k/min-history on backtest-equity CLI (use bounded path by default)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/fxhnt/cli.py

@@ -514,6 +514,8 @@ def backtest_equity(
     cost_bps: float = typer.Option(15.0, "--cost-bps", help="Cost in bps per unit (two-way) turnover."),
     borrow_annual: float = typer.Option(0.0, "--borrow-annual", help="Annual borrow cost on short notional."),
     out: str = typer.Option("/backtest-data/equity_backtest_report.json", "--out", help="Report JSON path."),
+    candidate_top_k: int = typer.Option(2000, help="Bounded candidate universe: top-K most-liquid names (caps memory; the full universe OOMs)."),
+    candidate_min_history: int = typer.Option(300, help="Min daily bars (close+volume) a name needs to be a candidate."),
 ) -> None:
     """B3b: walk-forward backtest of the 3 price-only equity-factor constructions against the DEDICATED
     survivorship-free backtest warehouse (settings.backtest_warehouse_path) -> gauntlet verdict + JSON report."""
@@ -527,6 +529,7 @@ def backtest_equity(
     try:
         result = EquityBacktestRunner(
             store, n=n, cost_bps_per_turnover=cost_bps, borrow_annual=borrow_annual,
+            candidate_top_k=candidate_top_k, candidate_min_history=candidate_min_history,
         ).run()
         report = evaluate_constructions(
             result,

tests/integration/test_backtest_equity_cli.py

@@ -57,3 +57,29 @@ def test_cli_backtest_equity_writes_report(tmp_path, monkeypatch) -> None:
     for block in report["constructions"].values():
         assert {"stats", "verdict"} <= set(block)
         assert {"passed", "dsr", "is_sharpe", "oos_sharpe"} <= set(block["verdict"])
+
+
+def test_cli_backtest_equity_bounded_candidate_flags(tmp_path, monkeypatch) -> None:
+    """The bounded memory pre-filter flags (--candidate-top-k / --candidate-min-history) are exposed
+    and passed to the runner; with thresholds the 3 synthetic names qualify -> full report."""
+    import fxhnt.cli as cli
+
+    wh = str(tmp_path / "wh.duckdb")
+    _build_warehouse(wh).close()
+    out = tmp_path / "report.json"
+
+    monkeypatch.setenv("FXHNT_BACKTEST_WAREHOUSE_PATH", wh)
+    cli.get_settings.cache_clear()  # settings are lru_cached — pick up the env override
+    res = CliRunner().invoke(
+        cli.app,
+        [
+            "backtest-equity", "--n", "10", "--out", str(out),
+            "--candidate-top-k", "100", "--candidate-min-history", "10",
+        ],
+    )
+    cli.get_settings.cache_clear()
+
+    assert res.exit_code == 0, res.output
+    assert out.exists(), "backtest-equity must write the report JSON at --out"
+    report = json.loads(out.read_text())
+    assert set(report["constructions"]) == {"long", "ls", "tilt"}