feat(marketplace): add cart hover dropdown preview

- Add CartDropdownContent component showing cart items on hover
- Show 'carrinho vazio' message when empty
- Display up to 4 items with name, quantity, price
- Add remove button for each item in dropdown
- Show total and 'Ver carrinho completo' link
- Badge only shows when cart has items (already implemented)

marketplace/src/layouts/Shell.tsx

@@ -2,6 +2,66 @@ import { useEffect, useRef, useState } from 'react'
 import { Link } from 'react-router-dom'
 import { useAuth } from '../context/AuthContext'
 import { useCartStore, selectCartSummary } from '../stores/cartStore'
+import { formatCurrency } from '../utils/format'
+
+// Cart dropdown content component
+function CartDropdownContent() {
+  const items = useCartStore((state) => state.items)
+  const removeItem = useCartStore((state) => state.removeItem)
+  const { totalValue } = useCartStore(selectCartSummary)
+
+  // Show max 4 items in preview
+  const displayItems = items.slice(0, 4)
+  const hiddenCount = items.length - displayItems.length
+
+  return (
+    <div>
+      <div className="p-3 border-b border-gray-100">
+        <p className="text-sm font-semibold text-gray-700">Carrinho</p>
+      </div>
+      <div className="max-h-64 overflow-y-auto">
+        {displayItems.map((item) => (
+          <div key={item.id} className="flex items-center gap-3 p-3 hover:bg-gray-50 border-b border-gray-50">
+            <div className="flex-1 min-w-0">
+              <p className="text-sm font-medium text-gray-800 truncate">{item.name}</p>
+              <p className="text-xs text-gray-500">{item.quantity}x • R$ {formatCurrency(item.unitPrice)}</p>
+            </div>
+            <button
+              onClick={(e) => {
+                e.preventDefault()
+                e.stopPropagation()
+                removeItem(item.id)
+              }}
+              className="text-red-500 hover:text-red-700 p-1"
+              title="Remover"
+            >
+              <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
+              </svg>
+            </button>
+          </div>
+        ))}
+        {hiddenCount > 0 && (
+          <div className="p-2 text-center text-xs text-gray-500">
+            +{hiddenCount} {hiddenCount === 1 ? 'item' : 'itens'}
+          </div>
+        )}
+      </div>
+      <div className="p-3 border-t border-gray-100 bg-gray-50">
+        <div className="flex justify-between items-center mb-3">
+          <span className="text-sm text-gray-600">Total:</span>
+          <span className="text-lg font-bold text-medicalBlue">R$ {formatCurrency(totalValue)}</span>
+        </div>
+        <Link
+          to="/cart"
+          className="block w-full text-center bg-medicalBlue text-white py-2 rounded-lg text-sm font-semibold hover:bg-blue-700 transition-colors"
+        >
+          Ver carrinho completo
+        </Link>
+      </div>
+    </div>
+  )
+}
 
 export function Shell({ children }: { children: React.ReactNode }) {
   const { user, logout } = useAuth()
@@ -58,16 +118,38 @@ export function Shell({ children }: { children: React.ReactNode }) {
               </Link>
             </>
           )}
-          <Link to="/cart" className="relative hover:bg-white/10 p-2 rounded-lg transition-colors" title="Carrinho">
+          {/* Cart with hover dropdown */}
-            <svg className="h-6 w-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+          <div className="relative group">
-              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M3 3h2l.4 2M7 13h10l4-8H5.4M7 13L5.4 5M7 13l-2.293 2.293c-.63.63-.184 1.707.707 1.707H17m0 0a2 2 0 100 4 2 2 0 000-4zm-8 2a2 2 0 11-4 0 2 2 0 014 0z" />
+            <Link
-            </svg>
+              to="/cart"
-            {cartCount > 0 && (
+              className="relative hover:bg-white/10 p-2 rounded-lg transition-colors block"
-              <span className="absolute -top-1 -right-1 flex h-5 w-5 items-center justify-center rounded-full bg-red-500 text-xs font-bold">
+              title="Carrinho"
-                {cartCount > 99 ? '99+' : cartCount}
+            >
-              </span>
+              <svg className="h-6 w-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-            )}
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M3 3h2l.4 2M7 13h10l4-8H5.4M7 13L5.4 5M7 13l-2.293 2.293c-.63.63-.184 1.707.707 1.707H17m0 0a2 2 0 100 4 2 2 0 000-4zm-8 2a2 2 0 11-4 0 2 2 0 014 0z" />
-          </Link>
+              </svg>
+              {cartCount > 0 && (
+                <span className="absolute -top-1 -right-1 flex h-5 w-5 items-center justify-center rounded-full bg-red-500 text-xs font-bold">
+                  {cartCount > 99 ? '99+' : cartCount}
+                </span>
+              )}
+            </Link>
+
+            {/* Dropdown on hover */}
+            <div className="invisible group-hover:visible opacity-0 group-hover:opacity-100 transition-all duration-200 absolute right-0 top-full z-50 mt-2 w-80 rounded-lg bg-white shadow-xl border border-gray-100">
+              {cartCount === 0 ? (
+                <div className="p-6 text-center">
+                  <svg className="mx-auto h-12 w-12 text-gray-300" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={1.5} d="M3 3h2l.4 2M7 13h10l4-8H5.4M7 13L5.4 5M7 13l-2.293 2.293c-.63.63-.184 1.707.707 1.707H17m0 0a2 2 0 100 4 2 2 0 000-4zm-8 2a2 2 0 11-4 0 2 2 0 014 0z" />
+                  </svg>
+                  <p className="mt-2 text-sm font-medium text-gray-600">Seu carrinho está vazio</p>
+                  <p className="text-xs text-gray-400">Adicione produtos para começar</p>
+                </div>
+              ) : (
+                <CartDropdownContent />
+              )}
+            </div>
+          </div>
           {user && (
             <div className="relative flex items-center" ref={profileMenuRef}>
               <button