feat(dashboard): the daily-overview band becomes opt-in

The hero renders only when the layout carries the literal
heroVisible: true. Legacy blobs without the field, malformed values,
and fresh accounts all keep it off; the Settings toggle persists an
explicit opt-in through the existing layout PUT.

src/components/settings/__tests__/dashboard-layout-section.test.tsx

@@ -299,17 +299,7 @@ describe("<DashboardLayoutSection> — hero visibility switch", () => {
     expect(en).toContain("Daily overview");
   });
 
-  it("reflects heroVisible: default layout → checked, false → unchecked", () => {
-    const checkedHtml = render(
-      <DashboardLayoutSection id="dashboard-layout" />,
-    );
-    const checked = checkedHtml.match(
-      /<button[^>]*data-slot="hero-visible-switch"[^>]*>/,
-    );
-    expect(checked).not.toBeNull();
-    expect(checked![0]).toContain('data-state="checked"');
-
-    queryState.layout = { ...DEFAULT_DASHBOARD_LAYOUT, heroVisible: false };
+  it("reflects heroVisible: default layout → unchecked, true → checked", () => {
     const uncheckedHtml = render(
       <DashboardLayoutSection id="dashboard-layout" />,
     );
@@ -318,6 +308,16 @@ describe("<DashboardLayoutSection> — hero visibility switch", () => {
     );
     expect(unchecked).not.toBeNull();
     expect(unchecked![0]).toContain('data-state="unchecked"');
+
+    queryState.layout = { ...DEFAULT_DASHBOARD_LAYOUT, heroVisible: true };
+    const checkedHtml = render(
+      <DashboardLayoutSection id="dashboard-layout" />,
+    );
+    const checked = checkedHtml.match(
+      /<button[^>]*data-slot="hero-visible-switch"[^>]*>/,
+    );
+    expect(checked).not.toBeNull();
+    expect(checked![0]).toContain('data-state="checked"');
   });
 
   it("persists through the existing PUT draft flow (source pins)", () => {

src/components/settings/dashboard-layout-section.tsx

@@ -408,7 +408,7 @@ export function DashboardLayoutSection({ id }: { id: string }) {
           </div>
           <Switch
             id={heroToggleId}
-            checked={layout.heroVisible !== false}
+            checked={layout.heroVisible === true}
             onCheckedChange={(v) => setHeroVisible(v)}
             disabled={saveMutation.isPending}
             data-slot="hero-visible-switch"