fix(gki): build the index from the glucose shown beside it

A reading entered in mmol/L is stored as whole mg/dL, and the index
divided the unrounded conversion, so a 5.2 / 0.3 pair printed beside a
17.4 rather than 17.3. Round the glucose to the decimal it is shown with
first and divide that. The tiles also printed a two-decimal ketone
reading to one decimal; show it as recorded.

src/components/day/day-gki-tile.tsx

@@ -4,7 +4,10 @@ import Link from "next/link";
 
 import type { DayResponse } from "@/lib/day/contract";
 import { useFormatters, useTranslations } from "@/lib/i18n/context";
-import { GKI_COMPONENT_UNIT } from "@/lib/measurements/glucose-ketone-index";
+import {
+  GKI_COMPONENT_UNIT,
+  ketoneFractionDigits,
+} from "@/lib/measurements/glucose-ketone-index";
 
 type DayGki = NonNullable<DayResponse["glucoseKetoneIndex"]>[number];
 
@@ -38,7 +41,10 @@ export function DayGkiTile({ points }: { points: readonly DayGki[] }) {
             ? tCount("day.gkiCount", points.length)
             : t("day.gkiPair", {
                 glucose: fmt.number(latest.glucoseMmol, 1),
-                ketones: fmt.number(latest.ketonesMmol, 1),
+                ketones: fmt.number(
+                  latest.ketonesMmol,
+                  ketoneFractionDigits(latest.ketonesMmol),
+                ),
                 unit: GKI_COMPONENT_UNIT,
               })}
         </span>

src/components/insights/ketones/gki-card.tsx

@@ -17,7 +17,10 @@ import {
 } from "@/components/ui/card";
 import { EmptyState } from "@/components/ui/empty-state";
 import { useFormatters, useTranslations } from "@/lib/i18n/context";
-import { GKI_COMPONENT_UNIT } from "@/lib/measurements/glucose-ketone-index";
+import {
+  GKI_COMPONENT_UNIT,
+  ketoneFractionDigits,
+} from "@/lib/measurements/glucose-ketone-index";
 import { useGlucoseKetoneIndexSeries } from "@/lib/queries/use-glucose-ketone-index";
 import { importWithRetry } from "@/lib/retry-import";
 
@@ -78,7 +81,10 @@ export function GkiCard() {
               {t("insights.bloodKetones.gki.latest", {
                 value: fmt.number(latest.value, 1),
                 glucose: fmt.number(latest.gki.glucoseMmol, 1),
-                ketones: fmt.number(latest.gki.ketonesMmol, 1),
+                ketones: fmt.number(
+                  latest.gki.ketonesMmol,
+                  ketoneFractionDigits(latest.gki.ketonesMmol),
+                ),
                 unit: GKI_COMPONENT_UNIT,
                 date: fmt.dateTime(latest.at),
               })}