fix(web): add aspect-ratio fallback for markdown inline images

packages/web/src/components/chat/MarkdownRenderer.tsx

@@ -187,14 +187,19 @@ function buildComponents(): Components {
 
     // Images (in markdown content — not attachments)
     img: ({ src, alt }) => (
+      <div
+        className="mt-1 rounded-md overflow-hidden bg-surface-input"
+        style={{ aspectRatio: '4/3', maxWidth: 400, maxHeight: 300 }}
+      >
         <img
           src={src}
           alt={alt ?? ''}
-        className="max-w-[400px] max-h-[300px] rounded-md mt-1"
+          className="w-full h-full object-contain"
           loading="lazy"
           referrerPolicy="no-referrer"
           crossOrigin="anonymous"
         />
+      </div>
     ),
 
     // Tables (GFM)