fix(selection): render gold brick chart as TDX brick blocks with strong-red flag

Match the ZXB1 sub-chart formula: each brick spans between yesterday's
and today's brick value via a stacked range bar — rising bricks are
hollow red (solid on strong_red), falling bricks solid green. The chart
API now also returns brick_strong_red per point.

zhixing-server/src/zhixing_server/modules/selection/application/chart.py

@@ -37,6 +37,7 @@ class SelectionChartPoint:
     trend_white: float | None
     trend_yellow: float | None
     brick_chart: float | None = None
+    brick_strong_red: bool | None = None
 
 
 @dataclass(frozen=True, slots=True)
@@ -95,7 +96,7 @@ class GetSelectionChart:
         )
         kdj = compute_kdj(frame)
         white, yellow = compute_zhixing_lines(frame["close"])
-        brick_chart = self._compute_brick_chart(ts_code, bars) if include_brick_chart else None
+        brick = self._compute_brick_indicators(ts_code, bars) if include_brick_chart else None
         start = max(0, len(bars) - SELECTION_CHART_LIMIT)
         points = tuple(
             SelectionChartPoint(
@@ -111,7 +112,10 @@ class GetSelectionChart:
                 trend_white=_finite_or_none(white.iloc[index]),
                 trend_yellow=_finite_or_none(yellow.iloc[index]),
                 brick_chart=(
-                    None if brick_chart is None else _finite_or_none(brick_chart.iloc[index])
+                    None if brick is None else _finite_or_none(brick["brick_chart"].iloc[index])
+                ),
+                brick_strong_red=(
+                    None if brick is None else _strong_red_or_none(brick["strong_red"].iloc[index])
                 ),
             )
             for index, bar in enumerate(bars)
@@ -125,11 +129,11 @@ class GetSelectionChart:
             points=points,
         )
 
-    def _compute_brick_chart(
+    def _compute_brick_indicators(
         self,
         ts_code: str,
         bars: tuple[SelectionBar, ...],
-    ) -> pd.Series:
+    ) -> pd.DataFrame:
         """Run the gold-brick formula on full history for stable warmup values."""
 
         frame = pd.DataFrame(
@@ -142,7 +146,16 @@ class GetSelectionChart:
                 "volume": [bar.volume for bar in bars],
             }
         )
-        return prepare_gold_brick_indicators(frame, ts_code)["brick_chart"]
+        prepared = prepare_gold_brick_indicators(frame, ts_code)
+        return prepared[["brick_chart", "strong_red"]]
+
+
+def _strong_red_or_none(value: object) -> bool | None:
+    """Convert one Pandas scalar to a JSON-safe brick flag or ``None``."""
+
+    if value is None or pd.isna(value):
+        return None
+    return bool(value)
 
 
 def _finite_or_none(value: object) -> float | None:

zhixing-server/src/zhixing_server/modules/selection/presentation/http.py

@@ -167,6 +167,7 @@ class SelectionChartPointResponse(BaseModel):
     trend_white: float | None
     trend_yellow: float | None
     brick_chart: float | None = None
+    brick_strong_red: bool | None = None
 
 
 class SelectionChartResponse(BaseModel):
@@ -510,6 +511,7 @@ def _chart_response(chart: SelectionChart) -> SelectionChartResponse:
                 trend_white=point.trend_white,
                 trend_yellow=point.trend_yellow,
                 brick_chart=point.brick_chart,
+                brick_strong_red=point.brick_strong_red,
             )
             for point in chart.points
         ],

zhixing-server/tests/test_selection_http.py

@@ -141,6 +141,7 @@ class FakeChartService:
                     trend_white=10.2,
                     trend_yellow=10.4,
                     brick_chart=5.0 if include_brick_chart else None,
+                    brick_strong_red=True if include_brick_chart else None,
                 ),
             ),
         )
@@ -462,6 +463,7 @@ def test_chart_returns_bounded_qfq_contract() -> None:
                 "trend_white": 10.2,
                 "trend_yellow": 10.4,
                 "brick_chart": None,
+                "brick_strong_red": None,
             }
         ],
     }
@@ -478,6 +480,7 @@ def test_chart_requests_brick_series_for_gold_brick_strategy() -> None:
     assert response.status_code == 200
     assert chart_service.request == ("000001.SZ", TARGET, True)
     assert response.json()["points"][0]["brick_chart"] == 5.0
+    assert response.json()["points"][0]["brick_strong_red"] is True
 
 
 @pytest.mark.parametrize(

zhixing-server/tests/unit/selection/test_chart.py

@@ -127,10 +127,15 @@ def test_chart_skips_brick_series_by_default_and_computes_on_request() -> None:
             "volume": [bar.volume for bar in history.bars],
         }
     )
-    expected = prepare_gold_brick_indicators(frame, history.ts_code)["brick_chart"]
-    assert brick_chart.points[-1].brick_chart == pytest.approx(float(expected.iloc[-1]))
+    prepared = prepare_gold_brick_indicators(frame, history.ts_code)
+    assert brick_chart.points[-1].brick_chart == pytest.approx(
+        float(prepared["brick_chart"].iloc[-1])
+    )
+    assert brick_chart.points[-1].brick_strong_red is bool(prepared["strong_red"].iloc[-1])
     assert brick_chart.points[0].trade_date == history.bars[10].trade_date
-    assert brick_chart.points[0].brick_chart == pytest.approx(float(expected.iloc[10]))
+    assert brick_chart.points[0].brick_chart == pytest.approx(
+        float(prepared["brick_chart"].iloc[10])
+    )
 
 
 def test_chart_rejects_empty_history() -> None: