feat(insights): recompute the stat strip for a brushed chart window

Wire the metric sub-pages so brushing a window in the chart recomputes the
Min/Max/Median/Mittelwert strip for the visible domain. The page lifts the
shared brushed-window state, passes `selectableDomain` + `onDomainStats` to
the chart, and threads the per-series window stats into the strip. With no
selection the strip keeps the precomputed full-range summary, so the default
is unchanged and costs no extra work.

The strip renders the windowed numbers when present and pins a "selected
range" pill to its header so the user reads the stats as their selection.
Blood pressure brushes both series at once — the single chart reports
systolic and diastolic stats and each strip reads its half.

Covers weight, pulse, blood pressure, and the ~37 HealthKit pages that ride
the shared scaffold. BMI (a derived metric with no first-class strip) and
sleep (no strip) are left as-is. New copy added in all six locales.

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

messages/de.json

@@ -1494,7 +1494,8 @@
       "sat": "Samstag",
       "sun": "Sonntag"
     },
-    "rangeBand": "Bereich"
+    "rangeBand": "Bereich",
+    "selectRange": "Zeitraum auswählen"
   },
   "chart": {
     "overlay": {
@@ -2104,7 +2105,8 @@
         "min": "Min",
         "max": "Max",
         "median": "Median",
-        "mean": "Mittelwert"
+        "mean": "Mittelwert",
+        "selectedRange": "Ausgewählter Bereich"
       },
       "showAllValues": "Alle Werte anzeigen",
       "valuesPageTitle": "{metric} — alle Werte",

messages/en.json

@@ -1494,7 +1494,8 @@
       "sat": "Saturday",
       "sun": "Sunday"
     },
-    "rangeBand": "Range"
+    "rangeBand": "Range",
+    "selectRange": "Select a range"
   },
   "chart": {
     "overlay": {
@@ -2104,7 +2105,8 @@
         "min": "Min",
         "max": "Max",
         "median": "Median",
-        "mean": "Mean"
+        "mean": "Mean",
+        "selectedRange": "Selected range"
       },
       "showAllValues": "Show all readings",
       "valuesPageTitle": "{metric} — all readings",

messages/es.json

@@ -1494,7 +1494,8 @@
       "sat": "Sábado",
       "sun": "Domingo"
     },
-    "rangeBand": "Rango"
+    "rangeBand": "Rango",
+    "selectRange": "Seleccionar un intervalo"
   },
   "chart": {
     "overlay": {
@@ -2104,7 +2105,8 @@
         "min": "Mín",
         "max": "Máx",
         "median": "Mediana",
-        "mean": "Media"
+        "mean": "Media",
+        "selectedRange": "Intervalo seleccionado"
       },
       "showAllValues": "Mostrar todas las mediciones",
       "valuesPageTitle": "{metric} — todas las mediciones",

messages/fr.json

@@ -1494,7 +1494,8 @@
       "sat": "Samedi",
       "sun": "Dimanche"
     },
-    "rangeBand": "Plage"
+    "rangeBand": "Plage",
+    "selectRange": "Sélectionner une plage"
   },
   "chart": {
     "overlay": {
@@ -2104,7 +2105,8 @@
         "min": "Min",
         "max": "Max",
         "median": "Médiane",
-        "mean": "Moyenne"
+        "mean": "Moyenne",
+        "selectedRange": "Plage sélectionnée"
       },
       "showAllValues": "Afficher toutes les mesures",
       "valuesPageTitle": "{metric} — toutes les mesures",

messages/it.json

@@ -1494,7 +1494,8 @@
       "sat": "Sabato",
       "sun": "Domenica"
     },
-    "rangeBand": "Intervallo"
+    "rangeBand": "Intervallo",
+    "selectRange": "Seleziona un intervallo"
   },
   "chart": {
     "overlay": {
@@ -2104,7 +2105,8 @@
         "min": "Min",
         "max": "Max",
         "median": "Mediana",
-        "mean": "Media"
+        "mean": "Media",
+        "selectedRange": "Intervallo selezionato"
       },
       "showAllValues": "Mostra tutte le misurazioni",
       "valuesPageTitle": "{metric} — tutte le misurazioni",

messages/pl.json

@@ -1494,7 +1494,8 @@
       "sat": "Sobota",
       "sun": "Niedziela"
     },
-    "rangeBand": "Zakres"
+    "rangeBand": "Zakres",
+    "selectRange": "Wybierz zakres"
   },
   "chart": {
     "overlay": {
@@ -2104,7 +2105,8 @@
         "min": "Min",
         "max": "Maks",
         "median": "Mediana",
-        "mean": "Średnia"
+        "mean": "Średnia",
+        "selectedRange": "Wybrany zakres"
       },
       "showAllValues": "Pokaż wszystkie pomiary",
       "valuesPageTitle": "{metric} — wszystkie pomiary",

src/app/insights/blood-pressure/page.tsx

@@ -7,6 +7,7 @@ import { useAuth } from "@/hooks/use-auth";
 import { useInsightsAnalytics } from "@/hooks/use-insights-analytics";
 import { useTranslations } from "@/lib/i18n/context";
 import { useInsightsLayoutPrefs } from "@/hooks/use-insights-layout-prefs";
+import { useChartDomainStats } from "@/hooks/use-chart-domain-stats";
 import { Button } from "@/components/ui/button";
 import { HealthChartDynamic } from "@/components/charts/health-chart-dynamic";
 import { SlugInsightStatusCard } from "@/components/insights/slug-insight-status-card";
@@ -50,6 +51,11 @@ export default function InsightsBlutdruckPage() {
   const sysSummary = analytics?.summaries?.BLOOD_PRESSURE_SYS ?? null;
   const diaSummary = analytics?.summaries?.BLOOD_PRESSURE_DIA ?? null;
 
+  // v1.12.7 — chart-reactive metric statistics. Blood pressure brushes BOTH
+  // series at once: the single chart reports per-type windowed stats and each
+  // strip reads its own half.
+  const { statsByType, onDomainStats } = useChartDomainStats();
+
   if (isEmpty) {
     return (
       <SubPageShell
@@ -113,6 +119,7 @@ export default function InsightsBlutdruckPage() {
             fractionDigits={0}
             seriesLabel={t("charts.systolic")}
             icon={ArrowUpRight}
+            windowStats={statsByType?.BLOOD_PRESSURE_SYS ?? null}
           />
           <MetricStatStrip
             summary={diaSummary}
@@ -120,6 +127,7 @@ export default function InsightsBlutdruckPage() {
             fractionDigits={0}
             seriesLabel={t("charts.diastolic")}
             icon={ArrowDownRight}
+            windowStats={statsByType?.BLOOD_PRESSURE_DIA ?? null}
           />
         </div>
       }
@@ -142,6 +150,8 @@ export default function InsightsBlutdruckPage() {
         targetZones={bpTargetZones}
         compareBaseline={compareBaseline}
         userTimezone={user?.timezone}
+        selectableDomain
+        onDomainStats={onDomainStats}
       />
 
       {/* v1.12.4 — target card sits between the chart and the assessment on

src/app/insights/pulse/page.tsx

@@ -7,6 +7,7 @@ import { useAuth } from "@/hooks/use-auth";
 import { useInsightsAnalytics } from "@/hooks/use-insights-analytics";
 import { useTranslations } from "@/lib/i18n/context";
 import { useInsightsLayoutPrefs } from "@/hooks/use-insights-layout-prefs";
+import { useChartDomainStats } from "@/hooks/use-chart-domain-stats";
 import { Button } from "@/components/ui/button";
 import { HealthChartDynamic } from "@/components/charts/health-chart-dynamic";
 import { SlugInsightStatusCard } from "@/components/insights/slug-insight-status-card";
@@ -50,6 +51,10 @@ export default function InsightsPulsPage() {
   const vo2Summary = analytics?.summaries?.VO2_MAX ?? null;
   const pulseSummary = analytics?.summaries?.PULSE ?? null;
 
+  // v1.12.7 — brushed-window stats shared between the pulse chart and the
+  // strip (the VO2 chart-row below keeps its own full-range read).
+  const { statsByType, onDomainStats } = useChartDomainStats();
+
   // v1.4.27 F17 — gate the sub-page on at least one pulse observation.
   // Brand-new accounts (no manual logs, no Apple-Health upload yet)
   // see a one-line empty-state with a CTA into
@@ -119,6 +124,7 @@ export default function InsightsPulsPage() {
           unit="bpm"
           seriesLabel={t("insights.pulseSectionTitle")}
           icon={Heart}
+          windowStats={statsByType?.PULSE ?? null}
         />
       }
       diversityNudge={
@@ -140,6 +146,8 @@ export default function InsightsPulsPage() {
         valueBands={pulseBands}
         compareBaseline={compareBaseline}
         userTimezone={user?.timezone}
+        selectableDomain
+        onDomainStats={onDomainStats}
       />
 
       <MetricTargetSummary slug="pulse" />

src/app/insights/weight/page.tsx

@@ -7,6 +7,7 @@ import { useAuth } from "@/hooks/use-auth";
 import { useInsightsAnalytics } from "@/hooks/use-insights-analytics";
 import { useTranslations } from "@/lib/i18n/context";
 import { useInsightsLayoutPrefs } from "@/hooks/use-insights-layout-prefs";
+import { useChartDomainStats } from "@/hooks/use-chart-domain-stats";
 import { Button } from "@/components/ui/button";
 import { HealthChartDynamic } from "@/components/charts/health-chart-dynamic";
 import { SlugInsightStatusCard } from "@/components/insights/slug-insight-status-card";
@@ -39,6 +40,9 @@ export default function InsightsGewichtPage() {
   const { data: analytics, isEmpty } = useInsightsAnalytics("WEIGHT");
   const weightSummary = analytics?.summaries?.WEIGHT ?? null;
 
+  // v1.12.7 — brushed-window stats shared between the chart and the strip.
+  const { statsByType, onDomainStats } = useChartDomainStats();
+
   if (isEmpty) {
     return (
       <SubPageShell
@@ -81,6 +85,7 @@ export default function InsightsGewichtPage() {
           unit="kg"
           seriesLabel={t("insights.weightSectionTitle")}
           icon={Scale}
+          windowStats={statsByType?.WEIGHT ?? null}
         />
       }
       diversityNudge={
@@ -102,6 +107,8 @@ export default function InsightsGewichtPage() {
         valueBands={weightBands}
         compareBaseline={compareBaseline}
         userTimezone={user?.timezone}
+        selectableDomain
+        onDomainStats={onDomainStats}
       />
 
       <MetricTargetSummary slug="weight" />

src/components/insights/healthkit-metric-page.tsx

@@ -8,6 +8,7 @@ import { Sparkles } from "lucide-react";
 import { useAuth } from "@/hooks/use-auth";
 import { useInsightsAnalytics } from "@/hooks/use-insights-analytics";
 import { useInsightsLayoutPrefs } from "@/hooks/use-insights-layout-prefs";
+import { useChartDomainStats } from "@/hooks/use-chart-domain-stats";
 import { useTranslations } from "@/lib/i18n/context";
 import type { InsightMetric } from "@/lib/insights/metric-availability";
 import type { MetricStatusMetricId } from "@/lib/insights/metric-status-registry";
@@ -165,6 +166,12 @@ export function HealthKitMetricPage({
 
   const { data: analytics, isEmpty } = useInsightsAnalytics(insightMetric);
 
+  // v1.12.7 — shared brushed-window state. The chart reports the per-type
+  // Min / Max / Median / Mean for the selected domain; the stat strip reads
+  // it back for this page's single series. No selection → null → the strip
+  // keeps the full-range summary.
+  const { statsByType, onDomainStats } = useChartDomainStats();
+
   const rawSummary = analytics?.summaries?.[measurementType] ?? null;
   // The stat strip renders display-unit values. The summary holds stored
   // values, so when the page renders a scaled unit (e.g. WALKING_SPEED
@@ -225,6 +232,7 @@ export function HealthKitMetricPage({
           unit={yAxisUnit ?? unit}
           seriesLabel={title}
           icon={statIcon}
+          windowStats={statsByType?.[measurementType] ?? null}
         />
       }
       diversityNudge={
@@ -248,6 +256,8 @@ export function HealthKitMetricPage({
         compareBaseline={compareBaseline}
         userTimezone={user?.timezone}
         valueScale={valueScale}
+        selectableDomain
+        onDomainStats={onDomainStats}
       />
       {targetSummarySlug ? (
         <MetricTargetSummary slug={targetSummarySlug} />

src/components/insights/metric-stat-strip.tsx

@@ -7,6 +7,7 @@ import { useFormatters, useTranslations } from "@/lib/i18n/context";
 import { Card, CardContent, CardHeader } from "@/components/ui/card";
 import { TileHeader } from "@/components/insights/tile-header";
 import type { DataSummary } from "@/lib/analytics/trends";
+import type { MetricWindowStats } from "@/lib/charts/window-stats";
 
 /**
  * v1.8.5 — at-a-glance stat strip for the insights category pages.
@@ -66,6 +67,17 @@ interface MetricStatStripProps {
    * complete header.
    */
   icon?: ComponentType<{ className?: string }>;
+  /**
+   * v1.12.7 — chart-reactive metric statistics. When the user brushes a
+   * window in the metric's chart, the sub-page lifts the chart's per-series
+   * Min / Max / Median / Mean for that window and threads it here. When
+   * present (non-null), the strip renders these windowed numbers in place of
+   * the full-range `summary` and swaps the header copy to "selected range" so
+   * the user reads the stats as describing their selection. Null (no
+   * selection) falls back to the cheap precomputed `summary` — the default,
+   * unchanged.
+   */
+  windowStats?: MetricWindowStats | null;
 }
 
 export function MetricStatStrip({
@@ -74,29 +86,37 @@ export function MetricStatStrip({
   fractionDigits = 1,
   seriesLabel,
   icon,
+  windowStats,
 }: MetricStatStripProps) {
   const { t } = useTranslations();
   const fmt = useFormatters();
 
   // Nothing to show until the summary lands or for a metric with no
-  // readings — the page's empty-state covers the zero-data case.
+  // readings — the page's empty-state covers the zero-data case. The gate
+  // rides the full-range summary even when a window is active, so a brush
+  // never resurrects the strip on a metric that has no data at all.
   if (!summary || summary.count <= 0) return null;
 
+  // v1.12.7 — a window selection with at least one reading wins over the
+  // full-range summary; otherwise the strip reads the precomputed numbers.
+  const windowed = windowStats != null && windowStats.count > 0;
+  const source = windowed ? windowStats : summary;
+
   const format = (value: number | null): string =>
     value === null ? "—" : `${fmt.number(value, fractionDigits)} ${unit}`;
 
   const cells: Array<{ key: string; label: string; value: number | null }> = [
-    { key: "min", label: t("insights.subPage.stats.min"), value: summary.min },
-    { key: "max", label: t("insights.subPage.stats.max"), value: summary.max },
+    { key: "min", label: t("insights.subPage.stats.min"), value: source.min },
+    { key: "max", label: t("insights.subPage.stats.max"), value: source.max },
     {
       key: "median",
       label: t("insights.subPage.stats.median"),
-      value: summary.median,
+      value: source.median,
     },
     {
       key: "mean",
       label: t("insights.subPage.stats.mean"),
-      value: summary.mean,
+      value: source.mean,
     },
   ];
 
@@ -107,6 +127,7 @@ export function MetricStatStrip({
     // data-slots; the section semantics ride on `role` + `aria-label`.
     <Card
       data-slot="metric-stat-strip"
+      data-windowed={windowed ? "true" : undefined}
       role="group"
       aria-label={
         seriesLabel
@@ -117,7 +138,24 @@ export function MetricStatStrip({
     >
       {seriesLabel ? (
         <CardHeader className="pb-2">
-          <TileHeader icon={icon ?? Sigma} title={seriesLabel} />
+          <TileHeader
+            icon={icon ?? Sigma}
+            title={seriesLabel}
+            // v1.12.7 — when the stats describe a brushed chart window rather
+            // than the full range, pin a "selected range" pill to the header
+            // so the user reads the numbers as their selection. Falls away the
+            // moment the selection clears.
+            right={
+              windowed ? (
+                <span
+                  data-slot="metric-stat-window-badge"
+                  className="bg-dracula-purple/10 text-dracula-purple rounded-md border border-current/30 px-1.5 py-0.5 text-[10px] font-medium tracking-wide uppercase"
+                >
+                  {t("insights.subPage.stats.selectedRange")}
+                </span>
+              ) : undefined
+            }
+          />
         </CardHeader>
       ) : null}
       <CardContent>