fix: use overflow-x:clip instead of hidden to fully contain blur blobs

overflow-x:hidden doesn't clip CSS blur() filter radius, allowing
blurred blobs to still cause horizontal scrollbar. overflow-x:clip
fully contains all rendered pixels including blur.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/index.css

@@ -62,10 +62,11 @@
 }
 
 @layer base {
-  html, body {
-    overflow-x: hidden;
+  html {
+    overflow-x: clip;
   }
   body {
+    overflow-x: clip;
     @apply font-sans text-slate-800 bg-slate-50 antialiased;
   }