chore: update social preview and docs homepage layout

- Redesign social-preview.png with polished amber brand theme
- Fix docs homepage layout ordering (hero → docker command → features)

apps/docs/.vitepress/theme/github-stars.css

@@ -1,7 +1,25 @@
+/* Move the docker command banner between hero and features */
+.VPHome {
+  display: flex;
+  flex-direction: column;
+}
+
+.VPHome > .VPHomeHero {
+  order: 0;
+}
+
+.VPHome > .vp-doc {
+  order: 1;
+}
+
+.VPHome > .VPHomeFeatures {
+  order: 2;
+}
+
 /* Quick start command banner on homepage */
 .quick-start-banner {
   max-width: 960px;
-  margin: -16px auto 48px;
+  margin: 0 auto 48px;
   padding: 0 24px;
   text-align: center;
 }