Add contract management and invoice settings pages

- Created a new Blade view for managing brand contracts with forms for adding and editing contracts, including client and category selection.
- Implemented success message notifications for contract actions.
- Added a new Blade view for invoice settings, allowing customization of invoice number format, header branding, and default values for new invoices.
- Introduced a new PDF view for generating rate cards with customizable styles based on user profile settings.
- Developed a profile management page for rate cards, enabling users to update their identity, appearance, and visibility settings.

app/Http/Controllers/ClientCategoryController.php

@@ -10,10 +10,18 @@ use Illuminate\Http\Request;
 
 class ClientCategoryController extends Controller
 {
-    public function index()
+    public function index(): \Illuminate\View\View
     {
-        // Managed inline from the clients page; redirect there
-        return redirect()->route('clients.index');
+        $categories = ClientCategory::with('children', 'parent')
+            ->withCount('clients')
+            ->orderBy('sort_order')
+            ->get();
+
+        $parents = ClientCategory::whereNull('parent_id')
+            ->orderBy('sort_order')
+            ->get();
+
+        return view('categories.index', compact('categories', 'parents'));
     }
 
     public function store(Request $request): RedirectResponse