feat: implement LiveTemperatureThresholdChart and add visibility policy unit tests

frontend/components/dashboard/scan-terminal/__tests__/temperatureDefaultVisibilityPolicy.test.ts

@@ -1,5 +1,7 @@
 import {
   __buildTemperatureChartDataForTest,
+  __getObservationDisplayMetricsForTest,
+  __getVisibleTemperatureSeriesForTest,
   __isTemperatureSeriesVisibleByDefaultForTest,
 } from "@/components/dashboard/scan-terminal/LiveTemperatureThresholdChart";
 
@@ -50,6 +52,7 @@ export function runTests() {
   } as any;
 
   const { series } = __buildTemperatureChartDataForTest(guangzhou, hourly, "1D");
+  const defaultVisibleSeries = __getVisibleTemperatureSeriesForTest("guangzhou", series, {});
 
   const settlementRunway = seriesByKey(series, "runway_02L_20R") as any;
   assert(settlementRunway, "settlement runway should use a stable runway-pair key");
@@ -82,6 +85,16 @@ export function runTests() {
     !__isTemperatureSeriesVisibleByDefaultForTest("guangzhou", "model_curve_ECMWF"),
     "multi-model curves should be hidden by default",
   );
+  assert(
+    !defaultVisibleSeries.some((item) => item.key === "model_curve_ECMWF"),
+    "hidden multi-model curves should not affect the active chart series by default",
+  );
+  assert(
+    __getVisibleTemperatureSeriesForTest("guangzhou", series, { model_curve_ECMWF: true }).some(
+      (item) => item.key === "model_curve_ECMWF",
+    ),
+    "users should still be able to enable a hidden multi-model curve from the legend",
+  );
   assert(
     __isTemperatureSeriesVisibleByDefaultForTest("paris", "model_curve_AROME HD"),
     "Paris AROME HD should be the only default-visible model curve exception",
@@ -107,4 +120,111 @@ export function runTests() {
   );
   assert(seriesByKey(shenzhen.series, "metar"), "Shenzhen/Lau Fau Shan observations should stay as METAR/HKO observations, not runway data");
   assert(!shenzhen.series.some((item) => item.key.startsWith("runway_")), "Shenzhen should not be treated as an AMSC runway city");
+
+  const chengduFromAmosSnapshot = __buildTemperatureChartDataForTest(
+    {
+      city: "chengdu",
+      local_date: "2026-05-26",
+      local_time: "05:25",
+      tz_offset_seconds: 8 * 60 * 60,
+      airport: "ZUUU",
+    } as any,
+    {
+      localTime: "05:25",
+      times: ["00:00", "06:00", "12:00", "18:00"],
+      temps: [24, 28, 31, 27],
+      amos: {
+        observation_time: "2026-05-25T21:25:00+00:00",
+        observation_time_local: "2026-05-26 05:25:00",
+        runway_obs: {
+          runway_pairs: [
+            ["02L", "20R"],
+            ["02R", "20L"],
+          ],
+          temperatures: [
+            [24.4, null],
+            [24.2, null],
+          ],
+          point_temperatures: [
+            { runway: "02L/20R", tdz_temp: 24.4, mid_temp: null, end_temp: 24.8 },
+            { runway: "02R/20L", tdz_temp: 24.2, mid_temp: null, end_temp: 24.6 },
+          ],
+        },
+      },
+    } as any,
+    "1D",
+  );
+
+  const chengduSettlementRunway = seriesByKey(chengduFromAmosSnapshot.series, "runway_02L_20R") as any;
+  assert(chengduSettlementRunway, "AMOS runway_obs snapshot should still create the settlement runway chart line");
+  assert(chengduSettlementRunway.color === "#009688", "AMOS snapshot settlement runway should use highlight cyan");
+  assert(chengduSettlementRunway.featured === true, "AMOS snapshot settlement runway should be featured");
+  assert(!chengduSettlementRunway.dashed, "AMOS snapshot settlement runway should be solid");
+
+  const chengduAuxRunway = seriesByKey(chengduFromAmosSnapshot.series, "runway_02R_20L") as any;
+  assert(chengduAuxRunway, "AMOS runway_obs snapshot should create auxiliary runway chart lines");
+  assert(chengduAuxRunway.dashed === true, "AMOS snapshot auxiliary runway should be dashed");
+
+  const newYorkMetrics = __getObservationDisplayMetricsForTest(
+    {
+      city: "new york",
+      local_date: "2026-05-25",
+      local_time: "17:30",
+      tz_offset_seconds: -4 * 60 * 60,
+      current_temp: 0,
+      current_max_so_far: 0,
+      metar_context: {
+        airport_max_so_far: 0,
+      },
+    } as any,
+    {
+      localTime: "17:30",
+      times: ["00:00"],
+      temps: [55],
+      airportCurrent: {
+        temp: 73.9,
+        max_so_far: 73.9,
+      },
+      metarTodayObs: [
+        { time: "16:51", temp: 73.9 },
+        { time: "15:51", temp: 73.0 },
+        { time: "00:34", temp: 55.0 },
+      ],
+    } as any,
+    null,
+  );
+
+  assert(newYorkMetrics.currentRunwayTemp === 73.9, "weather-station header should use detail METAR/current temp before stale row zero");
+  assert(newYorkMetrics.observedHighMetar === 73.9, "METAR high header should use detail METAR high before stale row zero");
+
+  const newYorkWithMadis = __buildTemperatureChartDataForTest(
+    {
+      city: "new york",
+      local_date: "2026-05-25",
+      local_time: "17:30",
+      tz_offset_seconds: -4 * 60 * 60,
+      airport: "KLGA",
+    } as any,
+    {
+      localTime: "17:30",
+      times: ["00:00", "06:00", "12:00", "18:00"],
+      temps: [55, 57, 65, 72],
+      airportPrimary: {
+        source_code: "madis_hfmetar",
+        source_label: "NOAA MADIS",
+      },
+      airportPrimaryTodayObs: [
+        ["16:51", 73.9],
+        ["15:51", 73],
+        ["15:47", 71.6],
+        ["15:44", 72],
+      ],
+      metarTodayObs: [{ time: "16:51", temp: 73.9 }],
+    } as any,
+    "1D",
+  );
+  const madisSeries = seriesByKey(newYorkWithMadis.series, "madis") as any;
+  assert(madisSeries, "US MADIS airport-primary observations should render as a dedicated chart series");
+  assert(madisSeries.label.includes("MADIS"), "US MADIS series should be labeled as NOAA MADIS instead of plain METAR");
+  assert(madisSeries.values.filter((value: number | null) => value !== null).length >= 2, "MADIS series should keep sub-hourly observations");
 }