feat(role): add role management demo and testing interface

- Introduced a new Role Management Test screen to interactively test role management operations.
- Implemented role addition, update, and removal functionalities with real-time policy evaluation.
- Enhanced the main app structure to include navigation to the Role Management Demo.
- Included comprehensive error handling and user feedback mechanisms for role management actions.

Author: dgarciasquare1

example/ROLE_MANAGEMENT_TEST.md

@@ -0,0 +1,91 @@
+# Role Management Test
+
+This dynamic test screen allows you to interactively test the role management operations from the Flutter Policy Engine.
+
+## Features
+
+### 1. Current Roles Display
+
+- Shows all currently available roles in the system
+- Displays permissions for each role
+- Click on any role to select it for testing or editing
+
+### 2. Role Management Operations
+
+Test the three main role management functions:
+
+#### Add Role
+
+- Enter a new role name and permissions
+- Permissions should be comma-separated (e.g., "LoginPage, Dashboard, Settings")
+- Click "Add Role" to create the new role
+
+#### Update Role
+
+- Select an existing role or enter a role name
+- Modify the permissions as needed
+- Click "Update Role" to apply changes
+
+#### Remove Role
+
+- Enter the name of the role to remove
+- Click "Remove Role" to delete it from the system
+
+### 3. Policy Testing
+
+- Select any role from the available roles
+- See real-time policy evaluation for different content types:
+  - Login Page
+  - Dashboard
+  - User Management
+  - Settings
+- Green cards indicate access granted
+- Red cards indicate access denied
+
+## Usage Examples
+
+### Adding a New Role
+
+1. Enter role name: "moderator"
+2. Enter permissions: "LoginPage, Dashboard, UserManagement"
+3. Click "Add Role"
+4. The new role appears in the Current Roles list
+
+### Testing Access Control
+
+1. Select "admin" role
+2. Observe that all content types show green (access granted)
+3. Switch to "guest" role
+4. Observe that only Login Page shows green, others show red (access denied)
+
+### Updating Permissions
+
+1. Click on "user" role in the Current Roles list
+2. The form will be populated with current permissions
+3. Add "Settings" to the permissions field
+4. Click "Update Role"
+5. Test the updated permissions in the Policy Testing section
+
+## Technical Details
+
+This test screen demonstrates:
+
+- `PolicyManager.addRole()` - Adding new roles
+- `PolicyManager.removeRole()` - Removing existing roles
+- `PolicyManager.updateRole()` - Updating role permissions
+- `PolicyWidget` - Real-time policy evaluation
+- Error handling and user feedback
+- Dynamic UI updates based on policy changes
+
+## Error Handling
+
+The test includes comprehensive error handling:
+
+- Validation for empty role names
+- Try-catch blocks for all operations
+- User-friendly status messages
+- Automatic status message clearing after 3 seconds
+
+## Integration
+
+This test screen is accessible from the main app home screen and provides a comprehensive way to validate the role management functionality of the Flutter Policy Engine.

example/lib/main.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_policy_engine_example/policy_engine_demo.dart';
+import 'package:flutter_policy_engine_example/role_management_demo.dart';
 
 void main() {
   runApp(const MyApp());
@@ -16,7 +17,90 @@ class MyApp extends StatelessWidget {
         colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
         useMaterial3: true,
       ),
-      home: const PolicyEngineDemo(),
+      home: const HomeScreen(),
+    );
+  }
+}
+
+class HomeScreen extends StatelessWidget {
+  const HomeScreen({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('Flutter Policy Engine Demo'),
+        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
+      ),
+      body: Padding(
+        padding: const EdgeInsets.all(16.0),
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            Card(
+              child: Padding(
+                padding: const EdgeInsets.all(16.0),
+                child: Column(
+                  children: [
+                    const Icon(
+                      Icons.security,
+                      size: 64,
+                      color: Colors.blue,
+                    ),
+                    const SizedBox(height: 16),
+                    Text(
+                      'Flutter Policy Engine',
+                      style: Theme.of(context).textTheme.headlineMedium,
+                      textAlign: TextAlign.center,
+                    ),
+                    const SizedBox(height: 8),
+                    Text(
+                      'Interactive demo and testing tools',
+                      style: Theme.of(context).textTheme.bodyLarge,
+                      textAlign: TextAlign.center,
+                    ),
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 24),
+            ElevatedButton.icon(
+              onPressed: () {
+                Navigator.push(
+                  context,
+                  MaterialPageRoute(
+                    builder: (context) => const PolicyEngineDemo(),
+                  ),
+                );
+              },
+              icon: const Icon(Icons.play_arrow),
+              label: const Text('Basic Policy Demo'),
+              style: ElevatedButton.styleFrom(
+                padding: const EdgeInsets.all(16),
+              ),
+            ),
+            const SizedBox(height: 16),
+            ElevatedButton.icon(
+              onPressed: () {
+                Navigator.push(
+                  context,
+                  MaterialPageRoute(
+                    builder: (context) => const RoleManagementDemo(),
+                  ),
+                );
+              },
+              icon: const Icon(Icons.admin_panel_settings),
+              label: const Text('Role Management Demo'),
+              style: ElevatedButton.styleFrom(
+                padding: const EdgeInsets.all(16),
+                backgroundColor: Colors.orange,
+                foregroundColor: Colors.white,
+              ),
+            ),
+          ],
+        ),
+      ),
     );
   }
 }