feat(insights): name the part of the day on the blood pressure stats while narrowed

The stat strip reads the chart's visible window, so with the chart
narrowed to the morning its figures were morning figures under a plain
Systolic label. The column label now says so. Russian texts for the
time-of-day card.

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

@@ -145,7 +145,7 @@ export default function InsightsBlutdruckPage() {
               summary: sysSummary,
               unit: "mmHg",
               fractionDigits: 0,
-              seriesLabel: t("charts.systolic"),
+              seriesLabel: timeOfDay.statsLabel(t("charts.systolic")),
               icon: ArrowUpRight,
               windowStats: statsByType?.BLOOD_PRESSURE_SYS ?? null,
               windowPending: !statsSettled,
@@ -155,7 +155,7 @@ export default function InsightsBlutdruckPage() {
               summary: diaSummary,
               unit: "mmHg",
               fractionDigits: 0,
-              seriesLabel: t("charts.diastolic"),
+              seriesLabel: timeOfDay.statsLabel(t("charts.diastolic")),
               icon: ArrowDownRight,
               windowStats: statsByType?.BLOOD_PRESSURE_DIA ?? null,
               windowPending: !statsSettled,

src/components/insights/blood-pressure/use-bp-time-of-day-state.ts

@@ -11,6 +11,7 @@ import {
   BP_PARTS_OF_DAY,
   type BpPartOfDay,
 } from "@/lib/analytics/bp-time-of-day";
+import { useTranslations } from "@/lib/i18n/context";
 import { useUrlSearch, writeUrlState } from "@/lib/url-state";
 
 /** The chart's part of the day, or the whole day. */
@@ -24,6 +25,13 @@ export function parseBpChartPart(
   return BP_PARTS_OF_DAY.find((part) => part === raw);
 }
 
+/** The stat strip's part-of-day word, so its figures say which readings they are. */
+const STATS_PART_KEYS: Record<BpPartOfDay, string> = {
+  morning: "insights.bpTimeOfDay.statsPart.morning",
+  midday: "insights.bpTimeOfDay.statsPart.midday",
+  evening: "insights.bpTimeOfDay.statsPart.evening",
+};
+
 const CHART_TITLE_KEYS: Record<BpPartOfDay, string> = {
   morning: "insights.bpTimeOfDay.chartTitle.morning",
   midday: "insights.bpTimeOfDay.chartTitle.midday",
@@ -45,8 +53,11 @@ export function useBpTimeOfDayState(): {
   /** The chart title's message key while narrowed; undefined for the whole day. */
   chartTitleKey: string | undefined;
   setChartPart: (next: BpChartPart) => void;
+  /** A stat column's label, naming the part of the day while narrowed. */
+  statsLabel: (series: string) => string;
   days: number;
 } {
+  const { t } = useTranslations();
   const partOfDay = parseBpChartPart(useUrlSearch());
   const setChartPart = useCallback((next: BpChartPart) => {
     writeUrlState(
@@ -63,6 +74,13 @@ export function useBpTimeOfDayState(): {
     partOfDay,
     chartTitleKey: partOfDay ? CHART_TITLE_KEYS[partOfDay] : undefined,
     setChartPart,
+    statsLabel: (series) =>
+      partOfDay
+        ? t("insights.bpTimeOfDay.statsLabel", {
+            series,
+            part: t(STATS_PART_KEYS[partOfDay]),
+          })
+        : series,
     days: rangeWindowDays(range),
   };
 }