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>

resources/views/layouts/admin.blade.php

@@ -46,11 +46,26 @@
                     <i class="bi bi-clipboard2-check-fill"></i> Set Soalselidik
                 </a>
             </li>
+
+            @if(auth()->user()->isSuperAdmin())
+            <li class="nav-item mt-2">
+                <small class="text-white-50 px-3" style="font-size:.7rem; text-transform:uppercase; letter-spacing:.8px;">Sistem</small>
+            </li>
+            <li class="nav-item">
+                <a href="{{ route('admin.users.index') }}"
+                   class="nav-link {{ request()->routeIs('admin.users.*') ? 'active' : '' }}">
+                    <i class="bi bi-people-fill"></i> Pengurusan Pengguna
+                </a>
+            </li>
+            @endif
         </ul>
 
         <div class="px-3 pb-3 mt-auto">
             <div class="border-top border-white border-opacity-25 pt-3">
                 <small class="text-white-50 d-block mb-1">{{ auth()->user()->name }}</small>
+                <span class="badge {{ auth()->user()->isSuperAdmin() ? 'bg-danger' : 'bg-primary' }} mb-2 d-inline-block">
+                    {{ auth()->user()->isSuperAdmin() ? 'Super Admin' : 'Admin Program' }}
+                </span>
                 <form method="POST" action="{{ route('logout') }}">
                     @csrf
                     <button type="submit" class="btn btn-sm btn-outline-light w-100">
@@ -145,6 +160,13 @@
                     <i class="bi bi-clipboard2-check-fill me-2"></i>Set Soalselidik
                 </a>
             </li>
+            @if(auth()->user()->isSuperAdmin())
+            <li class="nav-item">
+                <a href="{{ route('admin.users.index') }}" class="nav-link {{ request()->routeIs('admin.users.*') ? 'active' : '' }}" style="color:rgba(255,255,255,.85);">
+                    <i class="bi bi-people-fill me-2"></i>Pengurusan Pengguna
+                </a>
+            </li>
+            @endif
         </ul>
     </div>
 </div>