Never render a failed read as an absence of data

"No data yet" is a claim about the user's record. Making it when the
read failed states something false about their health history.

The mental-wellbeing surface was the one that mattered: the assessment
history read dropped isError entirely, so a failure left both
instrument cards showing "not taken yet" and the detail sheet showing
an empty trend. Someone with months of screening results was told, on
a mental-health surface, that the results did not exist. It now tells
loading, failed and genuinely empty apart, with a retry on the failure.

Also swept:
- the workouts insights page read isEmpty but not isError, so a failed
  list read fell through every branch to null and painted a titled
  shell with nothing in it;
- the micronutrients card (not in the original list) rendered its "no
  nutrient data" empty state on a failed read, while its sibling
  hydration card already used the shared error card;
- the medication detail page and the custom-metric values list showed
  an honest error with no way out. Both keep retry: false — right for
  a deleted row, wrong for a transient failure — and gain a
  user-initiated retry instead, which cannot storm;
- /achievements rendered a blank page on a direct hit with the module
  disabled. It now bounces to /insights like every other gated page.

The achievements query error branch, the custom-metric error branch and
the chronotype notice were already correct and are left alone.

src/app/achievements/page.tsx

@@ -34,6 +34,8 @@ import { EmptyState } from "@/components/ui/empty-state";
 import { PageHeader } from "@/components/ui/page-header";
 import { PageAuthGate } from "@/components/ui/page-auth-gate";
 import { QueryErrorCard } from "@/components/ui/query-error-card";
+import { useEffect } from "react";
+import { useRouter } from "next/navigation";
 import { useAuth } from "@/hooks/use-auth";
 import { useTranslations } from "@/lib/i18n/context";
 import { formatDate } from "@/lib/format";
@@ -260,6 +262,7 @@ function AchievementCard({ achievement, t }: AchievementCardProps) {
 export default function AchievementsPage() {
   const { user, isAuthenticated, isLoading: authLoading } = useAuth();
   const { t } = useTranslations();
+  const router = useRouter();
 
   // v1.18.0 — the achievements module gate. When the account has the
   // module turned off the whole page disappears: an empty state stands in
@@ -276,14 +279,26 @@ export default function AchievementsPage() {
     enabled: isAuthenticated && achievementsEnabled,
   });
 
+  useEffect(() => {
+    if (!authLoading && isAuthenticated && !achievementsEnabled) {
+      router.push("/insights");
+    }
+  }, [authLoading, isAuthenticated, achievementsEnabled, router]);
+
   if (authLoading || (achievementsEnabled && isLoading)) {
     return <PageAuthGate label={t("common.loading")} />;
   }
 
-  // v1.18.0 — module off ⇒ the surface disappears entirely. The nav entry
-  // is hidden by the same gate, so a direct hit on /achievements renders
-  // nothing rather than an orphaned shell. No new i18n string is minted
-  // (the disabled state has no copy of its own).
+  // v1.18.0 — module off ⇒ the surface disappears entirely. The nav entry is
+  // hidden by the same gate, so this only catches a direct URL hit. It used to
+  // render `null` and stop there, which left a blank page with no explanation
+  // and no route anywhere — a dead end rather than a gate. It now bounces to
+  // /insights, matching every other module-gated page (`useModulePageGuard`);
+  // the brief `null` is the pre-redirect frame, not the destination.
+  //
+  // The shared guard is not used wholesale here because it also redirects an
+  // unauthenticated visitor to /auth/login, and this page deliberately answers
+  // that case with a "sign in to see your achievements" header instead.
   if (isAuthenticated && !achievementsEnabled) {
     return null;
   }

src/app/insights/workouts/page-client.tsx

@@ -9,6 +9,7 @@ import { MetricEmptyState } from "@/components/insights/metric-empty-state";
 import { SubPageShell } from "@/components/insights/sub-page-shell";
 import { WorkoutList } from "@/components/insights/workout-list";
 import { Skeleton } from "@/components/ui/skeleton";
+import { QueryErrorCard } from "@/components/ui/query-error-card";
 
 /**
  * v1.4.32 — `/insights/workouts`.
@@ -36,7 +37,13 @@ import { Skeleton } from "@/components/ui/skeleton";
 export default function InsightsWorkoutsPageClient() {
   const { t } = useTranslations();
   const { ready } = useModulePageGuard("workouts");
-  const { data, isLoading, isEmpty } = useWorkouts({ limit: 100 });
+  // `isError` / `refetch` were already on the hook and simply not read here, so
+  // a failed list read fell through every branch to `null` and painted a titled
+  // shell with nothing in it — no message, no way back. Not the empty state,
+  // but just as opaque.
+  const { data, isLoading, isEmpty, isError, refetch } = useWorkouts({
+    limit: 100,
+  });
 
   // v1.18.0 B1 — bounce a direct URL hit on a disabled-workouts account.
   if (!ready) {
@@ -57,7 +64,12 @@ export default function InsightsWorkoutsPageClient() {
       {/* No `<MetricRangeControls>` here: workouts are session records, not a
           MeasurementType series, so the period-over-period range read has
           nothing to aggregate. */}
-      {isLoading ? (
+      {isError ? (
+        <QueryErrorCard
+          title={t("insights.workouts.loadError")}
+          onRetry={() => refetch()}
+        />
+      ) : isLoading ? (
         <div data-slot="workouts-loading" className="space-y-2">
           <Skeleton className="h-14 w-full rounded-lg" />
           <Skeleton className="h-14 w-full rounded-lg" />

src/app/medications/[id]/page.tsx

@@ -22,7 +22,7 @@ import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 
 import { BackLink } from "@/components/ui/back-link";
-import { Card } from "@/components/ui/card";
+import { QueryErrorCard } from "@/components/ui/query-error-card";
 import {
   MedicationDetailTabs,
   type MedicationDetailSnapshot,
@@ -49,6 +49,7 @@ export default function MedicationDetailPage({
     data: medication,
     isLoading,
     isError,
+    refetch,
   } = useQuery<MedicationDetailSnapshot>({
     queryKey: queryKeys.medicationDetail(id),
     queryFn: async () => {
@@ -71,20 +72,21 @@ export default function MedicationDetailPage({
     return <PageAuthGate label={t("common.loading")} />;
   }
 
+  // `retry: false` above stays: a deleted medication 404s here and automatic
+  // backoff against a row that no longer exists is pure waste. But that flag
+  // also stranded the page on a single transient failure, with no way forward
+  // short of navigating away and back. A user-initiated retry is the right
+  // granularity — it costs one request per click and cannot storm.
   if (isError || !medication) {
     return (
       <div className="space-y-6">
         <BackLink href="/medications" label={t("medications.back")} />
-        <Card
-          className="p-6"
-          role="alert"
-          aria-live="polite"
-          data-slot="medication-detail-error-card"
-        >
-          <p className="text-destructive text-sm">
-            {t("medications.detail.shell.loadFailed")}
-          </p>
-        </Card>
+        <div data-slot="medication-detail-error-card">
+          <QueryErrorCard
+            description={t("medications.detail.shell.loadFailed")}
+            onRetry={() => void refetch()}
+          />
+        </div>
       </div>
     );
   }

src/components/__tests__/failed-read-never-empty.test.tsx

@@ -0,0 +1,174 @@
+import { describe, it, expect, vi } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+
+import { I18nProvider } from "@/lib/i18n/context";
+import { queryKeys } from "@/lib/query-keys";
+import en from "../../../messages/en.json";
+
+/**
+ * A failed read must never render as an absence of data.
+ *
+ * "No data yet" is a factual claim about the user's record. Making it when the
+ * read failed is a false statement about their health history — worst of all on
+ * the mental-wellbeing surface, where a user with months of screening results
+ * was told, in a mental-health context, that they had never taken an
+ * assessment.
+ *
+ * Each surface must tell three states apart: loading, failed, and genuinely
+ * empty. These tests pin the failed/empty split; the loading branch is asserted
+ * where it is SSR-observable.
+ *
+ * SSR-only convention (`renderToStaticMarkup`, no `@testing-library/react`), so
+ * the error state is produced by seeding the query cache with a settled failure
+ * rather than by driving a real fetch.
+ */
+
+vi.mock("@/lib/api/api-fetch", () => ({
+  apiGet: () => new Promise(() => {}),
+  apiPost: () => new Promise(() => {}),
+}));
+
+vi.mock("@/hooks/use-auth", () => ({
+  useAuth: () => ({
+    user: { gender: "FEMALE", modules: {} },
+    isAuthenticated: true,
+    isLoading: false,
+  }),
+}));
+
+import { MentalWellbeing } from "@/components/mental-health/mental-wellbeing";
+import { MicronutrientsCard } from "@/components/insights/nutrients/micronutrients-card";
+
+function makeClient() {
+  return new QueryClient({
+    defaultOptions: {
+      queries: {
+        retry: false,
+        // An errored query would otherwise refetch on mount, and the observer
+        // reports that intent as an optimistic pending state during the server
+        // render — which would hide the very branch under test.
+        retryOnMount: false,
+        staleTime: Infinity,
+      },
+    },
+  });
+}
+
+/**
+ * Drive `queryKey` to a settled failure through the public prefetch path, so
+ * the SSR render below observes exactly the state a real failed read leaves in
+ * the cache.
+ */
+async function seedFailure(
+  client: QueryClient,
+  queryKey: readonly unknown[],
+): Promise<void> {
+  await client.prefetchQuery({
+    queryKey: queryKey as unknown[],
+    queryFn: () => Promise.reject(new Error("read failed")),
+    retry: false,
+  });
+}
+
+function render(node: React.ReactNode, client: QueryClient): string {
+  return renderToStaticMarkup(
+    <QueryClientProvider client={client}>
+      <I18nProvider initialLocale="en">{node}</I18nProvider>
+    </QueryClientProvider>,
+  );
+}
+
+describe("mental wellbeing — screening history", () => {
+  const mh = en.mentalHealth;
+
+  it("renders the error state with a retry when the history read fails", async () => {
+    const client = makeClient();
+    await seedFailure(client, queryKeys.mentalHealthAssessments());
+    const html = render(<MentalWellbeing />, client);
+
+    expect(html).toContain('data-slot="query-error-card"');
+    expect(html).toContain(mh.historyLoadError);
+    expect(html).toContain(en.common.retry);
+    // The load-bearing assertion: the instrument cards' "not taken yet" copy
+    // must NOT appear. That sentence is a claim about the user's record.
+    expect(html).not.toContain(mh.noResultYet);
+  });
+
+  it("still renders the instrument cards when the record is genuinely empty", () => {
+    const client = makeClient();
+    client.setQueryData(queryKeys.mentalHealthAssessments(), {
+      assessments: [],
+    });
+    const html = render(<MentalWellbeing />, client);
+
+    expect(html).not.toContain('data-slot="query-error-card"');
+    // An honest empty record: the cards render and invite a first check-in.
+    expect(html).toContain(mh.noResultYet);
+  });
+
+  it("shows neither the empty copy nor an error while the read is in flight", () => {
+    const html = render(<MentalWellbeing />, makeClient());
+    expect(html).not.toContain('data-slot="query-error-card"');
+    expect(html).not.toContain(mh.noResultYet);
+  });
+});
+
+describe("micronutrients card", () => {
+  const mn = en.nutrients.micronutrients;
+
+  it("renders the error state with a retry when the nutrient read fails", async () => {
+    const client = makeClient();
+    await seedFailure(client, queryKeys.nutrientIntake(30));
+    const html = render(<MicronutrientsCard />, client);
+
+    expect(html).toContain('data-slot="query-error-card"');
+    expect(html).toContain(mn.loadError);
+    expect(html).toContain(en.common.retry);
+    expect(html).not.toContain(mn.emptyTitle);
+  });
+
+  it("still renders the empty state when the record is genuinely empty", () => {
+    const client = makeClient();
+    client.setQueryData(queryKeys.nutrientIntake(30), { nutrients: [] });
+    const html = render(<MicronutrientsCard />, client);
+
+    expect(html).not.toContain('data-slot="query-error-card"');
+    expect(html).toContain(mn.emptyTitle);
+  });
+});
+
+/**
+ * The remaining surfaces in the sweep are pages whose render depends on the
+ * router / module gate, which the SSR-only convention cannot drive. Pin their
+ * contract structurally instead: each must read `isError` from its query and
+ * hand a retry to the shared error card, so a later edit cannot quietly drop
+ * the branch and fall back through to the empty state.
+ */
+describe("read-failure branch is wired on every swept surface", () => {
+  const surfaces = [
+    "src/components/mental-health/mental-wellbeing.tsx",
+    "src/app/insights/workouts/page-client.tsx",
+    "src/app/medications/[id]/page.tsx",
+    "src/components/custom-metrics/custom-metric-values-list.tsx",
+    "src/app/achievements/page.tsx",
+    "src/components/insights/nutrients/micronutrients-card.tsx",
+    "src/components/insights/sleep/chronotype-section.tsx",
+  ] as const;
+
+  for (const rel of surfaces) {
+    it(`${rel} reads isError and offers a retry`, () => {
+      const source = readFileSync(join(process.cwd(), rel), "utf8");
+      expect(source).toMatch(/isError/);
+      // chronotype-section is the one surface that legitimately renders an
+      // inline notice rather than the card (it sits inside a chart section),
+      // so it is exempt from the retry affordance but not from the branch.
+      if (!rel.endsWith("chronotype-section.tsx")) {
+        expect(source).toMatch(/onRetry=/);
+        expect(source).toMatch(/refetch/);
+      }
+    });
+  }
+});

src/components/custom-metrics/custom-metric-values-list.tsx

@@ -6,6 +6,7 @@ import { useInfiniteQuery, useQuery } from "@tanstack/react-query";
 import { Button } from "@/components/ui/button";
 import { Card, CardContent } from "@/components/ui/card";
 import { Skeleton } from "@/components/ui/skeleton";
+import { QueryErrorCard } from "@/components/ui/query-error-card";
 import { apiGet } from "@/lib/api/api-fetch";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
@@ -41,6 +42,7 @@ export function CustomMetricValuesList({
     data: list,
     isLoading,
     isError,
+    refetch,
     fetchNextPage,
     hasNextPage,
     isFetchingNextPage,
@@ -68,11 +70,15 @@ export function CustomMetricValuesList({
   );
   const total = list?.pages[0]?.meta.total ?? 0;
 
+  // The error state was honest but a dead end: one red sentence, no way to try
+  // again short of navigating away and back. QueryErrorCard carries the same
+  // message with a retry, matching the sibling custom-metric list.
   if (isError) {
     return (
-      <p className="text-destructive py-8 text-center text-sm">
-        {t("customMetrics.loadError")}
-      </p>
+      <QueryErrorCard
+        description={t("customMetrics.loadError")}
+        onRetry={() => void refetch()}
+      />
     );
   }
 

src/components/insights/nutrients/micronutrients-card.tsx

@@ -5,6 +5,7 @@ import { Leaf } from "lucide-react";
 
 import { Card, CardContent, CardHeader } from "@/components/ui/card";
 import { EmptyState } from "@/components/ui/empty-state";
+import { QueryErrorCard } from "@/components/ui/query-error-card";
 import { Skeleton } from "@/components/ui/skeleton";
 import { TileHeader } from "@/components/insights/tile-header";
 import { useAuth } from "@/hooks/use-auth";
@@ -53,7 +54,11 @@ export function MicronutrientsCard() {
   const sex =
     user?.gender === "MALE" || user?.gender === "FEMALE" ? user.gender : null;
 
-  const { data, isLoading } = useQuery({
+  // A failed read left `data` undefined, `rows` empty, and the card rendered
+  // its "no micronutrient data" EmptyState — the same output as an account that
+  // genuinely logs no nutrients. The sibling hydration card already routes
+  // through QueryErrorCard; this one now matches it.
+  const { data, isLoading, isError, refetch } = useQuery({
     queryKey: queryKeys.nutrientIntake(WINDOW_DAYS),
     queryFn: () =>
       apiGet<NutrientIntakeOverview>(`/api/nutrients?days=${WINDOW_DAYS}`),
@@ -72,7 +77,12 @@ export function MicronutrientsCard() {
         <TileHeader icon={Leaf} title={t("nutrients.micronutrients.title")} />
       </CardHeader>
       <CardContent className="space-y-3">
-        {isLoading ? (
+        {isError ? (
+          <QueryErrorCard
+            title={t("nutrients.micronutrients.loadError")}
+            onRetry={() => void refetch()}
+          />
+        ) : isLoading ? (
           <div className="space-y-1" aria-hidden="true">
             <Skeleton className="h-9 w-full rounded-md" />
             <Skeleton className="h-9 w-full rounded-md" />

src/components/mental-health/mental-wellbeing.tsx

@@ -38,6 +38,8 @@ import { queryKeys } from "@/lib/query-keys";
 import { INSTRUMENTS, INSTRUMENT_ORDER } from "@/lib/mental-health/instruments";
 import { PageHeader } from "@/components/ui/page-header";
 import { ResponsiveSheet } from "@/components/ui/responsive-sheet";
+import { QueryErrorCard } from "@/components/ui/query-error-card";
+import { Skeleton } from "@/components/ui/skeleton";
 
 import { AssessmentResult } from "./assessment-result";
 import { CheckInWizard } from "./check-in-wizard";
@@ -63,7 +65,20 @@ export function MentalWellbeing() {
     null,
   );
 
-  const { data: history } = useQuery({
+  // The three states are kept apart deliberately. This read carries the user's
+  // screening history; when it fails, `history` is undefined and every
+  // downstream consumer (`lastByInstrument`, the detail sheet's `rows`) sees an
+  // empty array — which used to render the instrument cards' "not taken yet"
+  // copy. On a mental-health surface that is not a missing error message, it is
+  // a false statement about the user's record: someone with months of
+  // assessments was told the assessments do not exist. Error is now rendered as
+  // error, loading as loading, and only a genuinely empty result as empty.
+  const {
+    data: history,
+    isPending: historyPending,
+    isError: historyError,
+    refetch: refetchHistory,
+  } = useQuery({
     queryKey: queryKeys.mentalHealthAssessments(),
     queryFn: () =>
       apiGet<{ assessments: AssessmentRow[] }>(
@@ -131,18 +146,37 @@ export function MentalWellbeing() {
 
           <section aria-label={t("mentalHealth.choosePrompt")}>
             <h2 className="sr-only">{t("mentalHealth.choosePrompt")}</h2>
-            <ul className="grid list-none gap-4 p-0 sm:grid-cols-2">
-              {INSTRUMENT_ORDER.map((id) => (
-                <li key={id} className="contents">
-                  <InstrumentCard
-                    instrument={id}
-                    last={lastByInstrument.get(id)}
-                    onStart={() => begin(id)}
-                    onOpenDetail={() => setDetailInstrument(id)}
-                  />
-                </li>
-              ))}
-            </ul>
+            {historyError ? (
+              <QueryErrorCard
+                title={t("mentalHealth.historyLoadError")}
+                description={t("mentalHealth.historyLoadErrorHint")}
+                onRetry={() => void refetchHistory()}
+              />
+            ) : historyPending ? (
+              <ul
+                className="grid list-none gap-4 p-0 sm:grid-cols-2"
+                aria-busy="true"
+              >
+                {INSTRUMENT_ORDER.map((id) => (
+                  <li key={id} className="contents">
+                    <Skeleton className="h-44 w-full rounded-xl" />
+                  </li>
+                ))}
+              </ul>
+            ) : (
+              <ul className="grid list-none gap-4 p-0 sm:grid-cols-2">
+                {INSTRUMENT_ORDER.map((id) => (
+                  <li key={id} className="contents">
+                    <InstrumentCard
+                      instrument={id}
+                      last={lastByInstrument.get(id)}
+                      onStart={() => begin(id)}
+                      onOpenDetail={() => setDetailInstrument(id)}
+                    />
+                  </li>
+                ))}
+              </ul>
+            )}
           </section>
 
           {/* 2026-07-17 UX/IA audit M9 — mood tracking, this screener surface,