feat: add PlaceholderCreatePage widget

Author: fulleni

lib/shared/widgets/placeholder_create_page.dart

@@ -0,0 +1,24 @@
+import 'package:flutter/material.dart';
+
+/// {@template placeholder_create_page}
+/// A simple placeholder page for content creation forms.
+/// {@endtemplate}
+class PlaceholderCreatePage extends StatelessWidget {
+  /// {@macro placeholder_create_page}
+  const PlaceholderCreatePage({required this.title, super.key});
+
+  /// The title to display on the page.
+  final String title;
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(title),
+      ),
+      body: Center(
+        child: Text('Form for "$title" will go here.'),
+      ),
+    );
+  }
+}