feat: two-role system — super_admin & admin program (Fasa 12)

- Replace is_admin boolean with role enum('super_admin','admin') via migration
- ProgramPolicy: admin program can only view/edit/delete own programs
- EnsureIsAdmin: accepts both roles; EnsureSuperAdmin: super_admin only
- UserController + views: super_admin can manage admin accounts
- Sidebar: user management link & role badge gated on isSuperAdmin()
- Fix Controller base class: add AuthorizesRequests trait
- Fix tests: replace nonAdmin() (invalid enum) with adminProgram() against super_admin-only route

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/Feature/AuthTest.php

@@ -27,12 +27,12 @@ class AuthTest extends TestCase
         $this->get('/admin/dashboard')->assertRedirect('/login');
     }
 
-    public function test_non_admin_cannot_access_admin_routes(): void
+    public function test_admin_program_cannot_access_user_management(): void
     {
-        $user = User::factory()->nonAdmin()->create();
+        $admin = User::factory()->adminProgram()->create();
 
-        $this->actingAs($user)
-            ->get('/admin/dashboard')
+        $this->actingAs($admin)
+            ->get('/admin/users')
             ->assertForbidden();
     }