QA fixes: real listing creation, profile save, favorites, missing pages

- SellItemPage: real file upload + API listing creation + activate
- CreateProfilePage: save profile via PUT /users/profile
- ProductDetailPage: wire edit/delete/message buttons, show edit for owner
- ListingCard: persist favorites via API, show real images
- Footer: connect newsletter subscribe to API
- Router: add /dashboard/listings and /dashboard/saved routes
- Backend: add GET /listings/favorites endpoint
- New pages: MyListingsPage, SavedItemsPage
- Fix unused imports causing build failures

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/src/pages/SavedItemsPage.tsx

@@ -0,0 +1,39 @@
+import { useState, useEffect } from 'react';
+import { Card } from '../components/ui/Card';
+import { ListingCard } from '../components/listings/ListingCard';
+import { api } from '../api/client';
+import type { Listing, PaginatedResponse } from '../types';
+
+export function SavedItemsPage() {
+  const [listings, setListings] = useState<Listing[]>([]);
+  const [loading, setLoading] = useState(true);
+
+  useEffect(() => {
+    api.get<PaginatedResponse<Listing>>('/listings/favorites')
+      .then(res => setListings(res.data))
+      .catch(() => {})
+      .finally(() => setLoading(false));
+  }, []);
+
+  if (loading) return <div className="text-center py-12 text-gray-500">Loading...</div>;
+
+  return (
+    <div>
+      <h1 className="text-2xl font-bold text-gray-900 mb-6">Saved Items</h1>
+
+      {listings.length === 0 ? (
+        <Card>
+          <div className="text-center py-8">
+            <p className="text-gray-500">No saved items yet. Browse listings and tap the heart to save items you like.</p>
+          </div>
+        </Card>
+      ) : (
+        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-4">
+          {listings.map(listing => (
+            <ListingCard key={listing.id} listing={listing} />
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}