fix(a11y): a labelled rail row says its label and the exact unread count, not the capped badge first (E28)

With the labels on, the row's name was its text, badge first: 15 unread was heard as "9+ Alerts". The
name is now the visible label plus the count, as the icon-only row's is, and the drawn badge is hidden.

frontend/src/components/ui/NavRail.dom.test.tsx

@@ -46,6 +46,22 @@ describe("NavRailItem", () => {
     const row = screen.getByRole("button", { name: "Alerts" });
     expect(row.getAttribute("aria-current")).toBeNull();
   });
+
+  // E28 audit: labelled, the name was the row's text, the corner badge first, so 20 unread was heard
+  // as "9+Alerts" where the icon-only row says "Notifications (20)".
+  it("labelled with a count: the visible label, then the exact count", () => {
+    render(
+      <NavRailItem
+        icon={Bell}
+        label="Notifications"
+        shortLabel="Alerts"
+        showLabel
+        badge={20}
+        onClick={() => {}}
+      />,
+    );
+    expect(screen.getByRole("button", { name: "Alerts (20)" })).toBeTruthy();
+  });
 });
 
 // F32: the rail's footer (language, About, Sign out) drew 32 and 36 squares with 16 and 20px glyphs

frontend/src/components/ui/NavRail.tsx

@@ -97,10 +97,11 @@ export function NavRailItem({
       <Pressable
         data-testid={testId}
         onClick={onClick}
-        // With the label visible the row's name IS that text (WCAG 2.5.3: the spoken name contains the
-        // visible one); the full name stays in the tooltip. Icon-only, the full name is the name.
-        // The count rides in the name too, so "Messages, 3" is heard and not only seen.
-        aria-label={showLabel ? undefined : shown ? `${label} (${badge})` : label}
+        // With the label visible the row's name starts with that text (WCAG 2.5.3: the spoken name
+        // contains the visible one); the full name stays in the tooltip. Icon-only, the full name is the
+        // name. The exact count rides in the name either way, so "Messages (3)" is heard and not only
+        // seen; the drawn badge is hidden (labelled, it was read first and capped: "9+Alerts").
+        aria-label={`${showLabel ? shortLabel : label}${shown ? ` (${badge})` : ""}`}
         aria-current={active ? "page" : undefined}
         className={clsx(
           RAIL_ROW,
@@ -117,7 +118,10 @@ export function NavRailItem({
         <span className="relative shrink-0">
           <Icon className={RAIL_GLYPH} aria-hidden="true" />
           {shown && (
-            <span className="absolute -top-2 -right-2 grid h-4 min-w-4 place-items-center rounded-full bg-accent px-1 text-3xs leading-none font-bold text-accent-fg ring-2 ring-bg">
+            <span
+              aria-hidden="true"
+              className="absolute -top-2 -right-2 grid h-4 min-w-4 place-items-center rounded-full bg-accent px-1 text-3xs leading-none font-bold text-accent-fg ring-2 ring-bg"
+            >
               {badge > 9 ? "9+" : badge}
             </span>
           )}