fix(charts): read the 7-day range as daily rows

On a per-minute heart-rate stream the 7-day chart showed only the first
half of the week. The range read raw rows oldest-first under a
5000-row limit, and seven days of per-minute samples are 10 080 rows,
so the newest days never arrived.

The chart folds every range into days anyway, so the 7-day range now
asks for one row per local day like the longer ranges. The whole week
arrives whatever the sampling rate, and the 7-day and 30-day ranges
share one day boundary and one source pick per day. The 7-day range
still draws no spread band, so its picture is unchanged.

Refs #1026

tests/integration/chart-range-dense.test.ts

@@ -0,0 +1,106 @@
+/**
+ * The chart's own request, against the real route, on a dense stream.
+ *
+ * The 7-day range used to ask for raw rows oldest-first with a 5 000-row
+ * limit. Per-minute heart rate puts 10 080 rows in seven days, so the answer
+ * stopped about three and a half days in and the chart silently lost the
+ * most recent days. Every range now asks for one row per local day, so the
+ * whole window arrives whatever the sampling rate.
+ */
+import { NextRequest } from "next/server";
+import { beforeAll, describe, expect, it, vi } from "vitest";
+
+import { cookieJar } from "./mock-next-headers";
+import { getPrismaClient, truncateAllTables } from "./setup";
+import { chartSeriesParams } from "@/components/charts/chart-series-request";
+import { userDayKey } from "@/lib/tz/format";
+import { invalidateUserTimezone } from "@/lib/tz/resolver";
+
+vi.mock("next/headers", async () => {
+  const { cookieJar, headerJar } = await import("./mock-next-headers");
+  return {
+    headers: vi.fn(async () => ({
+      get: (name: string) => headerJar.get(name.toLowerCase()) ?? null,
+    })),
+    cookies: vi.fn(async () => ({
+      get: (name: string) => {
+        const value = cookieJar.get(name);
+        return value ? { name, value } : undefined;
+      },
+      set: (name: string, value: string) => {
+        cookieJar.set(name, value);
+      },
+      delete: (name: string) => {
+        cookieJar.delete(name);
+      },
+    })),
+  };
+});
+
+vi.mock("@/lib/db-compat", () => ({
+  ensureDbCompatibility: vi.fn().mockResolvedValue(undefined),
+}));
+
+const USER = "chart-range-dense-user";
+const TZ = "Europe/Berlin";
+const TO = new Date("2026-09-20T18:00:00.000Z");
+const MINUTES = 7 * 24 * 60;
+
+beforeAll(async () => {
+  const prisma = getPrismaClient();
+  await truncateAllTables(prisma);
+  cookieJar.clear();
+  await prisma.user.create({
+    data: { id: USER, username: USER, timezone: TZ },
+  });
+  invalidateUserTimezone(USER);
+  const session = await prisma.session.create({
+    data: { userId: USER, expiresAt: new Date(Date.now() + 3_600_000) },
+  });
+  cookieJar.set("healthlog_session", session.id);
+  await prisma.$executeRawUnsafe(
+    `INSERT INTO measurements (
+       id, user_id, type, value, unit, source, measured_at,
+       created_at, updated_at, sync_version)
+     SELECT 'cr' || lpad(g::text, 6, '0'), $1, 'PULSE'::measurement_type,
+       60 + (g % 30), 'bpm', 'GOOGLE_HEALTH'::measurement_source,
+       ($2::timestamptz AT TIME ZONE 'UTC') - (g * interval '1 minute'),
+       now(), now(), 1
+     FROM generate_series(0, $3::int - 1) g`,
+    USER,
+    TO.toISOString(),
+    MINUTES,
+  );
+}, 120_000);
+
+describe("7-day chart range on per-minute pulse", () => {
+  it("returns every day of the window, the newest included", async () => {
+    const from = new Date(TO.getTime() - 7 * 86_400_000);
+    const params = chartSeriesParams("PULSE", {
+      from: from.toISOString(),
+      to: TO.toISOString(),
+    });
+    const { GET } = await import("@/app/api/measurements/route");
+    const res = await GET(
+      new NextRequest(`http://localhost/api/measurements?${params}`),
+    );
+    expect(res.status).toBe(200);
+    const json = (await res.json()) as {
+      data: { measurements: Array<{ measuredAt: string }> };
+    };
+    const days = new Set(
+      json.data.measurements.map((m) => userDayKey(new Date(m.measuredAt), TZ)),
+    );
+    // 20 Sep 20:00 Berlin back to 13 Sep 20:00: eight calendar days.
+    expect([...days].sort()).toEqual([
+      "2026-09-13",
+      "2026-09-14",
+      "2026-09-15",
+      "2026-09-16",
+      "2026-09-17",
+      "2026-09-18",
+      "2026-09-19",
+      "2026-09-20",
+    ]);
+  });
+});