refactor(dashboard): retire the legacy opt-in hero

The digest-driven Today hero is the single promoted hero at the top of
the dashboard, so the old opt-in hero band is redundant — a user who had
opted in and has Insights on saw two heroes. Remove the legacy hero and
its heroVisible layout flag.

- Drop the DashboardHero / DashboardHeroSkeleton mount from the
  dashboard page; the header now renders the greeting unconditionally
  (its showGreeting gate is gone with the hero that owned it).
- Retire the heroVisible field from the dashboard layout (type,
  defaults, resolver, serializer) and the widgets PUT schema. The
  resolver is a whitelist constructor, so a stored heroVisible is
  dropped on read and never re-persisted — no stored layout breaks.
- Delete the now-orphaned hero components (band, skeleton, ring
  carousel, briefing spotlight) and their tests; drop the retired
  dashboard.hero copy across all locales.
- Remove the hero-visibility toggle from Settings → Dashboard. The
  score-ring picker no longer hangs off that flag and stays available,
  since the rings it configures still ride the server-computed
  dashboard snapshot.
- Repoint the phone-width density guard at the Today hero and mock the
  daily digest so it renders.
- Repoint the preserve-when-absent doc analogy off the removed field.

src/app/api/dashboard/widgets/__tests__/route.test.ts

@@ -407,132 +407,6 @@ describe("PUT /api/dashboard/widgets — accept-and-ignore unknown ids (v1.7.0 #
 
 const callGet = GET as unknown as () => Promise<Response>;
 
-describe("PUT /api/dashboard/widgets — heroVisible thread-through", () => {
-  const knownId = DASHBOARD_WIDGET_IDS[0];
-
-  it("persists an explicit heroVisible: false WITHOUT dropping stored chartOverlayPrefs", async () => {
-    // The regression class this route already guards for
-    // `chartOverlayPrefs`: a layout PUT that omits a sibling field must
-    // not wipe it. heroVisible sent + prefs omitted → prefs merge from
-    // the stored blob, heroVisible persists from the body.
-    const storedPrefs = {
-      bp: {
-        showTrendIndicator: true,
-        showTrendArrow: false,
-        showTargetRange: true,
-        comparisonBaseline: "lastMonth" as const,
-      },
-    };
-    vi.mocked(prisma.user.findUnique).mockResolvedValue({
-      dashboardWidgetsJson: serializeDashboardLayout({
-        version: 1,
-        widgets: [{ id: knownId, visible: true, order: 0 }],
-        chartOverlayPrefs: storedPrefs,
-      }),
-    } as never);
-    vi.mocked(prisma.user.update).mockResolvedValue({} as never);
-
-    const res = await callPut(
-      makeReq({
-        version: 1,
-        widgets: [{ id: knownId, visible: true, order: 0 }],
-        heroVisible: false,
-      }),
-    );
-    expect(res.status).toBe(200);
-
-    const updateArg = vi.mocked(prisma.user.update).mock
-      .calls[0]?.[0] as unknown as {
-      data: {
-        dashboardWidgetsJson: {
-          heroVisible: boolean;
-          chartOverlayPrefs: Record<string, unknown>;
-        };
-      };
-    };
-    expect(updateArg.data.dashboardWidgetsJson.heroVisible).toBe(false);
-    expect(updateArg.data.dashboardWidgetsJson.chartOverlayPrefs).toEqual(
-      storedPrefs,
-    );
-
-    // The response echoes the persisted value.
-    const body = (await res.json()) as { data: { heroVisible: boolean } };
-    expect(body.data.heroVisible).toBe(false);
-  });
-
-  it("preserves a stored heroVisible: false when the PUT omits the field", async () => {
-    vi.mocked(prisma.user.findUnique).mockResolvedValue({
-      dashboardWidgetsJson: serializeDashboardLayout({
-        version: 1,
-        widgets: [{ id: knownId, visible: true, order: 0 }],
-        heroVisible: false,
-      }),
-    } as never);
-    vi.mocked(prisma.user.update).mockResolvedValue({} as never);
-
-    const res = await callPut(
-      makeReq({
-        version: 1,
-        widgets: [{ id: knownId, visible: true, order: 0 }],
-      }),
-    );
-    expect(res.status).toBe(200);
-
-    const updateArg = vi.mocked(prisma.user.update).mock
-      .calls[0]?.[0] as unknown as {
-      data: { dashboardWidgetsJson: { heroVisible: boolean } };
-    };
-    expect(updateArg.data.dashboardWidgetsJson.heroVisible).toBe(false);
-  });
-
-  it("defaults heroVisible to false for a first save with no stored layout", async () => {
-    vi.mocked(prisma.user.findUnique).mockResolvedValue({
-      dashboardWidgetsJson: null,
-    } as never);
-    vi.mocked(prisma.user.update).mockResolvedValue({} as never);
-
-    const res = await callPut(
-      makeReq({
-        version: 1,
-        widgets: [{ id: knownId, visible: true, order: 0 }],
-      }),
-    );
-    expect(res.status).toBe(200);
-
-    const updateArg = vi.mocked(prisma.user.update).mock
-      .calls[0]?.[0] as unknown as {
-      data: { dashboardWidgetsJson: { heroVisible: boolean } };
-    };
-    expect(updateArg.data.dashboardWidgetsJson.heroVisible).toBe(false);
-  });
-
-  it("422s on a non-boolean heroVisible", async () => {
-    const res = await callPut(
-      makeReq({
-        version: 1,
-        widgets: [{ id: knownId, visible: true, order: 0 }],
-        heroVisible: "yes",
-      }),
-    );
-    expect(res.status).toBe(422);
-  });
-
-  it("GET resolves heroVisible alongside the widget layout", async () => {
-    vi.mocked(prisma.user.findUnique).mockResolvedValue({
-      dashboardWidgetsJson: serializeDashboardLayout({
-        version: 1,
-        widgets: [{ id: knownId, visible: true, order: 0 }],
-        heroVisible: false,
-      }),
-    } as never);
-
-    const res = await callGet();
-    expect(res.status).toBe(200);
-    const body = (await res.json()) as { data: { heroVisible: boolean } };
-    expect(body.data.heroVisible).toBe(false);
-  });
-});
-
 describe("dashboard widgets — 27-id catalogue round-trip (v1.7.0 W1)", () => {
   it("PUT of a full 27-id layout persists every id (iOS-only round-trip)", async () => {
     vi.mocked(prisma.user.findUnique).mockResolvedValue({

src/app/api/dashboard/widgets/route.ts

@@ -121,14 +121,8 @@ const layoutSchema = z.object({
       }),
     )
     .optional(),
-  // Dashboard hero (daily verdict) visibility. Optional so clients
-  // that predate the field can still PUT; when omitted the handler
-  // preserves the stored value (same preserve-when-absent contract as
-  // `chartOverlayPrefs` — a Settings save that doesn't know the field
-  // must not silently reset the user's choice).
-  heroVisible: z.boolean().optional(),
   // v1.27.7 — hero score rings (max 3, closed id set). Optional with the
-  // same preserve-when-absent contract as `heroVisible`; the resolver
+  // same preserve-when-absent contract as `chartOverlayPrefs`; the resolver
   // dedupes on read/serialize, `.max()` bounds the wire length.
   selectedScoreRings: z
     .array(z.enum(SCORE_RING_IDS))
@@ -284,19 +278,17 @@ export const PUT = apiHandler(async (request: NextRequest) => {
   // didn't send. The dashboard-layout PUT typically saves widget
   // visibility / order; chart prefs are PUT through their own route
   // (`/api/dashboard/chart-overlay-prefs`) and would otherwise be
-  // wiped here on a subsequent layout save. `heroVisible` and
-  // `selectedScoreRings` ride the same preserve-when-absent contract —
-  // an older client's layout save must not reset either choice. One
+  // wiped here on a subsequent layout save. `selectedScoreRings` and
+  // `heroRingOrder` ride the same preserve-when-absent contract — an
+  // older client's layout save must not reset either choice. One
   // stored-layout read covers all fallbacks.
   let mergedChartOverlayPrefs: ChartOverlayPrefsMap | undefined = parsed.data
     .chartOverlayPrefs as ChartOverlayPrefsMap | undefined;
-  let mergedHeroVisible: boolean | undefined = parsed.data.heroVisible;
   let mergedScoreRings: ScoreRingId[] | undefined =
     parsed.data.selectedScoreRings;
   let mergedHeroRingOrder: HeroRingId[] | undefined = parsed.data.heroRingOrder;
   if (
     mergedChartOverlayPrefs === undefined ||
-    mergedHeroVisible === undefined ||
     mergedScoreRings === undefined ||
     mergedHeroRingOrder === undefined
   ) {
@@ -310,9 +302,6 @@ export const PUT = apiHandler(async (request: NextRequest) => {
     if (mergedChartOverlayPrefs === undefined) {
       mergedChartOverlayPrefs = existingLayout.chartOverlayPrefs ?? {};
     }
-    if (mergedHeroVisible === undefined) {
-      mergedHeroVisible = existingLayout.heroVisible === true;
-    }
     if (mergedScoreRings === undefined) {
       mergedScoreRings = existingLayout.selectedScoreRings;
     }
@@ -323,7 +312,6 @@ export const PUT = apiHandler(async (request: NextRequest) => {
   const normalized = serializeDashboardLayout({
     ...parsed.data,
     chartOverlayPrefs: mergedChartOverlayPrefs,
-    heroVisible: mergedHeroVisible,
     selectedScoreRings: mergedScoreRings,
     heroRingOrder: mergedHeroRingOrder,
   } as DashboardLayout);

src/app/api/medications/layout/route.ts

@@ -4,7 +4,7 @@
  * GET returns the resolved presentation (view + manual order, defaults
  * merged in if the user hasn't customised yet). PUT updates it with
  * preserve-when-absent semantics — a view-only PUT keeps the stored
- * order and vice versa, matching the `heroVisible` contract on
+ * order and vice versa, matching the `chartOverlayPrefs` contract on
  * `/api/dashboard/widgets`. DELETE resets to default.
  *
  * Mirrors the shape and semantics of `/api/insights/layout`; the blob
@@ -42,7 +42,7 @@ const layoutSchema = z.object({
   version: z.literal(1),
   // Both fields are optional so a client can PUT exactly the field it
   // changed; the handler merges the absent one from the stored blob
-  // (preserve-when-absent, like `heroVisible` on the dashboard layout).
+  // (preserve-when-absent, like `chartOverlayPrefs` on the dashboard layout).
   view: z.enum(MEDICATION_LIST_VIEWS).optional(),
   // Medication ids are opaque here — display-only ordering, unknown /
   // deleted ids are ignored at apply time, so the schema bounds size