fix: match storybook layout pattern for AG-UI stories

Use absolute positioning with dark:bg-gray-950 wrapper to match the
layout pattern used by all other Console stories. The previous height:
80vh approach didn't work with Storybook's centered layout mode.

https://claude.ai/code/session_015b5wa5VYLPgMqspBpffpSj

Author: claude

stories/AgUi.stories.tsx

@@ -28,8 +28,20 @@ export const Basic = () => {
   });
 
   return (
-    <div style={{ height: '80vh' }}>
-      <div style={{ padding: '8px 0' }}>
+    <div
+      className="dark:bg-gray-950 bg-white"
+      style={{
+        position: 'absolute',
+        top: 0,
+        left: 0,
+        right: 0,
+        bottom: 0,
+        padding: 20,
+        margin: 20,
+        borderRadius: 5
+      }}
+    >
+      <div style={{ paddingBottom: 8 }}>
         <Input
           placeholder="AG-UI agent endpoint URL"
           value={endpoint}
@@ -98,8 +110,20 @@ export const WithToolCalls = () => {
   });
 
   return (
-    <div style={{ height: '80vh' }}>
-      <div style={{ padding: '8px 0' }}>
+    <div
+      className="dark:bg-gray-950 bg-white"
+      style={{
+        position: 'absolute',
+        top: 0,
+        left: 0,
+        right: 0,
+        bottom: 0,
+        padding: 20,
+        margin: 20,
+        borderRadius: 5
+      }}
+    >
+      <div style={{ paddingBottom: 8 }}>
         <Input
           placeholder="AG-UI agent endpoint URL"
           value={endpoint}