fix: adding the missing file

Author: pavanpodila

packages/demo/lib/embed_wrapper.dart

@@ -0,0 +1,106 @@
+import 'package:flutter/material.dart';
+
+import 'example_model.dart';
+
+/// Minimal wrapper for embedding examples in iframes.
+///
+/// Shows the example with minimal chrome - just the example content
+/// and optionally a small header with title and source link.
+class EmbedWrapper extends StatelessWidget {
+  final Example example;
+  final bool showHeader;
+  final VoidCallback? onSourceTap;
+
+  const EmbedWrapper({
+    super.key,
+    required this.example,
+    this.showHeader = true,
+    this.onSourceTap,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      backgroundColor: theme.colorScheme.surface,
+      body: Column(
+        children: [
+          // Minimal header for embedded view
+          if (showHeader)
+            Container(
+              height: 40,
+              padding: const EdgeInsets.symmetric(horizontal: 12),
+              decoration: BoxDecoration(
+                color: theme.colorScheme.surfaceContainerHighest,
+                border: Border(
+                  bottom: BorderSide(
+                    color: theme.colorScheme.outlineVariant,
+                    width: 1,
+                  ),
+                ),
+              ),
+              child: Row(
+                children: [
+                  if (example.icon != null) ...[
+                    Icon(
+                      example.icon,
+                      size: 16,
+                      color: theme.colorScheme.primary,
+                    ),
+                    const SizedBox(width: 8),
+                  ],
+                  Expanded(
+                    child: Text(
+                      example.title,
+                      style: theme.textTheme.titleSmall?.copyWith(
+                        fontWeight: FontWeight.w600,
+                        color: theme.colorScheme.onSurface,
+                      ),
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                    ),
+                  ),
+                  if (onSourceTap != null)
+                    TextButton.icon(
+                      onPressed: onSourceTap,
+                      icon: Icon(
+                        Icons.code,
+                        size: 16,
+                        color: theme.colorScheme.primary,
+                      ),
+                      label: Text(
+                        'Source',
+                        style: TextStyle(
+                          fontSize: 12,
+                          color: theme.colorScheme.primary,
+                        ),
+                      ),
+                      style: TextButton.styleFrom(
+                        padding: const EdgeInsets.symmetric(horizontal: 8),
+                        minimumSize: Size.zero,
+                        tapTargetSize: MaterialTapTargetSize.shrinkWrap,
+                      ),
+                    ),
+                ],
+              ),
+            ),
+          // Example content
+          Expanded(child: example.builder(context)),
+        ],
+      ),
+    );
+  }
+}
+
+/// Embed wrapper without any header - just the raw example.
+class EmbedWrapperMinimal extends StatelessWidget {
+  final Example example;
+
+  const EmbedWrapperMinimal({super.key, required this.example});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(body: example.builder(context));
+  }
+}