test(insights): freeze the clock in the freshness-caption tests to fix the midnight-boundary flake

src/components/insights/__tests__/daily-briefing.test.tsx

@@ -131,13 +131,22 @@ describe("<DailyBriefing>", () => {
 
   it("renders the 'Updated today, <time>' caption when updatedAt is supplied", () => {
     // v1.22 (W6) — the footer now uses `formatUpdatedLabel`: a same-day
-    // timestamp reads "Updated today, HH:MM".
-    const fiveMinutesAgo = new Date(Date.now() - 5 * 60_000).toISOString();
-    const html = render(
-      <DailyBriefing briefing={baseBriefing} updatedAt={fiveMinutesAgo} />,
-    );
-    expect(html).toMatch(/data-slot="daily-briefing-updated"/);
-    expect(html).toContain("Updated today");
+    // timestamp reads "Updated today, HH:MM". The label derives "today" from the
+    // real clock in the profile timezone (Europe/Berlin), so freeze the clock to
+    // a fixed mid-day instant and base `updatedAt` on it — otherwise a run that
+    // straddles local midnight reads the five-minutes-ago stamp as "yesterday".
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date("2026-05-10T12:00:00+02:00"));
+    try {
+      const fiveMinutesAgo = new Date(Date.now() - 5 * 60_000).toISOString();
+      const html = render(
+        <DailyBriefing briefing={baseBriefing} updatedAt={fiveMinutesAgo} />,
+      );
+      expect(html).toMatch(/data-slot="daily-briefing-updated"/);
+      expect(html).toContain("Updated today");
+    } finally {
+      vi.useRealTimers();
+    }
   });
 
   it("does NOT render the updated caption when updatedAt is missing", () => {

src/components/insights/__tests__/hero-strip.test.tsx

@@ -108,16 +108,26 @@ describe("<HeroStrip>", () => {
     // v1.22 — the hero freshness line now uses `formatUpdatedLabel` for parity
     // with the briefing + per-metric cards: a same-day timestamp reads
     // "Updated today, HH:MM" rather than the old relative "Generated … ago".
-    const fiveMinutesAgo = new Date(Date.now() - 5 * 60_000).toISOString();
-    const html = render(
-      <HeroStrip
-        briefing={null}
-        updatedAt={fiveMinutesAgo}
-        now={morningLocal}
-      />,
-    );
-    expect(html).toMatch(/data-slot="insights-hero-strip-generated"/);
-    expect(html).toContain("Updated today");
+    // `formatUpdatedLabel` derives "today" from the real clock, so freeze it to a
+    // fixed instant and base `updatedAt` on the same instant — otherwise a run
+    // that straddles local midnight reads the five-minutes-ago stamp as
+    // "yesterday".
+    vi.useFakeTimers();
+    vi.setSystemTime(morningLocal);
+    try {
+      const fiveMinutesAgo = new Date(Date.now() - 5 * 60_000).toISOString();
+      const html = render(
+        <HeroStrip
+          briefing={null}
+          updatedAt={fiveMinutesAgo}
+          now={morningLocal}
+        />,
+      );
+      expect(html).toMatch(/data-slot="insights-hero-strip-generated"/);
+      expect(html).toContain("Updated today");
+    } finally {
+      vi.useRealTimers();
+    }
   });
 
   it("does NOT render the generated caption when updatedAt is missing", () => {