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

next.config.js

@@ -3,23 +3,23 @@ export default {
   typescript: {
     ignoreBuildErrors: true,
   },
-  images: { 
-    unoptimized: true,
+  images: {
     remotePatterns: [
-    {
-      protocol: 'https',
-      hostname: 'images.unsplash.com',
-    },
-    {
-      protocol: 'https',
-      hostname: 'cdn.shopify.com',
-    },
-    {
-      protocol: 'https',
-      hostname: '**.frontend.co',
-    },
-  ], 
-  }, 
+      {
+        protocol: 'https',
+        hostname: 'images.unsplash.com',
+      },
+      // Covers cdn.shopify.com plus any other Shopify-hosted image subdomain.
+      {
+        protocol: 'https',
+        hostname: '**.shopify.com',
+      },
+      {
+        protocol: 'https',
+        hostname: '**.frontend.co',
+      },
+    ],
+  },
   experimental: { 
     reactDebugChannel: false 
   },