Render Shopify imagery through next/image

Turn the optimizer back on by dropping images.unoptimized, and widen the
Shopify remote pattern to **.shopify.com so any image subdomain resolves.
With the optimizer live, remotePatterns is now actually enforced.

Convert the seven Shopify CDN call sites: the product/collection cards and
the gallery carousel size with fill + sizes, while the cart, order and
search thumbnails carry explicit dimensions. The avatar, markdown,
attachment, assistant and logo images stay plain <img> — they take
blob:/data: or arbitrary hosts that next/image cannot process.

The lightbox needs w-auto h-auto: the width and height attributes
next/image requires make both axes definite, so max-w/max-h clamp them
independently instead of preserving the ratio. object-contain masked that,
but the stretched element covered the overlay and ate the backdrop clicks
that close the dialog.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015uSQQNWrmiYDRW9L9VnsGC

components/shopify/search-dialog.tsx

@@ -1,6 +1,7 @@
 'use client';
 
 import React, { useEffect, useRef, useState } from 'react';
+import Image from 'next/image';
 import { useRouter } from 'next/navigation';
 import {
   CommandDialog,
@@ -162,9 +163,11 @@ const SearchDialog: React.FC = () => {
                     >
                       <div className="h-14 w-14 shrink-0 overflow-hidden bg-zinc-100">
                         {product.featuredImage ? (
-                          <img
+                          <Image
                             src={product.featuredImage.url}
                             alt={product.featuredImage.altText || product.title}
+                            width={56}
+                            height={56}
                             className="h-full w-full object-cover"
                           />
                         ) : (