feat(frontend): wire KeyboardCheatsheet into Claims page via ? toggle

src/pages/Claims.tsx

@@ -19,6 +19,7 @@ import {
 import { StatusBadge } from "@/components/StatusBadge";
 import { NewClaimDialog } from "@/components/NewClaimDialog";
 import { ClaimDrawer } from "@/components/ClaimDrawer";
+import { KeyboardCheatsheet } from "@/components/KeyboardCheatsheet";
 import { Skeleton } from "@/components/ui/skeleton";
 import { EmptyState } from "@/components/ui/empty-state";
 import { ErrorState } from "@/components/ui/error-state";
@@ -48,6 +49,7 @@ export function Claims() {
   const [npi, setNpi] = useState<string>(ALL);
   const [query, setQuery] = useState("");
   const [page, setPage] = useState(1);
+  const [helpOpen, setHelpOpen] = useState(false);
   const searchRef = useRef<HTMLInputElement>(null);
 
   // SP4 drawer wiring: the URL is the source of truth for "which claim is
@@ -114,9 +116,11 @@ export function Claims() {
         claims={items.map((c) => ({ id: c.id }))}
         onClose={close}
         onNavigate={setClaimId}
-        onToggleHelp={() => {
-          // T22 wires the KeyboardCheatsheet overlay; no-op for now.
-        }}
+        onToggleHelp={() => setHelpOpen((v) => !v)}
+      />
+      <KeyboardCheatsheet
+        open={helpOpen}
+        onClose={() => setHelpOpen(false)}
       />
       <div
         data-testid="claims-page-body"