fix: add hero_image live editing with Image component from emdash/ui

Use Image component instead of img tag. Add hero_image to hero-visual
container with {...homepage.edit.hero_image} for live editing.

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

src/pages/index.astro

@@ -1,5 +1,6 @@
 ---
 import { getEmDashEntry } from "emdash";
+import { Image } from "emdash/ui";
 import Base from "../layouts/Base.astro";
 
 const { entry: homepage } = await getEmDashEntry("homepage", "main");
@@ -33,7 +34,11 @@ const d = homepage.data;
           </a>
         </div>
       </div>
-      <div class="hero-visual">
+      <div class="hero-visual" {...homepage.edit.hero_image}>
+        {d.hero_image?.src && (
+          <Image image={d.hero_image} />
+        )}
+        {!d.hero_image?.src && (
           <div class="code-window">
           <div class="code-header">
             <span class="dot red"></span>