Task #19: Donation cart (سلة تبرعاتك) for EHSAN POC

Built a real donation cart matching ehsan.sa:
- CartContext provider (localStorage-persisted, defensive parsing) wired into App.tsx
- OpportunityCard: cart icon now adds the case with its typed amount and swaps the
  action row to an added state («مضاف لسلة تبرعاتك» + «إزالة»)
- Header cart button: live count badge + navigates to /cart
- New /cart page + route: breadcrumb, item list (delete icon, category, name,
  editable «قيمة المبلغ» amount, image+progress%), summary panel «الإجمالي» +
  green «للمتابعة للدفع», decorative leaf SVG background, empty state
- translations.ts: parallel AR+EN `cart` section
- donate.tsx: removes the donated case from the cart on successful donation
  (cart reconciliation), preventing stale added-state/badge

Notes/deviations:
- Checkout handoff routes the first cart item into the existing single-case donate
  flow (the POC backend has no multi-item payment). Reconciliation keeps remaining
  items coherent. A true multi-item checkout backend was out of scope.
- Verified with passing e2e test (add → badge → cart page → remove → empty) and
  clean tsc; architect review addressed (reconciliation + defensive parsing).

artifacts/ehsan-poc/src/App.tsx

@@ -3,6 +3,7 @@ import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { Toaster } from "@/components/ui/toaster";
 import { TooltipProvider } from "@/components/ui/tooltip";
 import { LanguageProvider } from "./contexts/LanguageContext";
+import { CartProvider } from "./contexts/CartContext";
 import { AuthProvider, useAuth } from "./contexts/AuthContext";
 import { AppLayout } from "./components/layout/AppLayout";
 import NotFound from "@/pages/not-found";
@@ -19,6 +20,7 @@ import Track from "./pages/track";
 import ThankYou from "./pages/thank-you";
 import WhatsappLog from "./pages/whatsapp-log";
 import Login from "./pages/login";
+import Cart from "./pages/cart";
 
 const queryClient = new QueryClient();
 
@@ -39,6 +41,7 @@ function Router() {
         <Route path="/request" component={RequestSupport} />
         <Route path="/opportunities" component={Opportunities} />
         <Route path="/donate/:id" component={Donate} />
+        <Route path="/cart" component={Cart} />
         <Route path="/login" component={Login} />
         <Route path="/admin">
           <Protected component={Admin} />
@@ -59,12 +62,14 @@ function App() {
     <QueryClientProvider client={queryClient}>
       <LanguageProvider>
         <AuthProvider>
-          <TooltipProvider>
-            <WouterRouter base={import.meta.env.BASE_URL.replace(/\/$/, "")}>
-              <Router />
-            </WouterRouter>
-            <Toaster />
-          </TooltipProvider>
+          <CartProvider>
+            <TooltipProvider>
+              <WouterRouter base={import.meta.env.BASE_URL.replace(/\/$/, "")}>
+                <Router />
+              </WouterRouter>
+              <Toaster />
+            </TooltipProvider>
+          </CartProvider>
         </AuthProvider>
       </LanguageProvider>
     </QueryClientProvider>