refactor: add return type hints to all controller methods

Added proper return types (View, RedirectResponse, JsonResponse, Collection)
to 40+ controller methods across 16 controllers. Also added missing
imports for Illuminate response types and tightened parameter types
(e.g. InstallationController::showStep now uses int instead of mixed).

app/Http/Controllers/Community/Staff/StaffApplicationsController.php

@@ -5,6 +5,7 @@ namespace App\Http\Controllers\Community\Staff;
 use App\Http\Controllers\Controller;
 use App\Models\Community\Staff\WebsiteOpenPosition;
 use App\Models\Community\Staff\WebsiteStaffApplications;
+use Illuminate\Http\RedirectResponse;
 use Illuminate\Http\Request;
 use Illuminate\View\View;
 
@@ -32,7 +33,7 @@ class StaffApplicationsController extends Controller
         return view('community.staff-apply', ['position' => $position]);
     }
 
-    public function store(Request $request, WebsiteOpenPosition $position)
+    public function store(Request $request, WebsiteOpenPosition $position): RedirectResponse
     {
         abort_unless($position->position_kind === 'rank', 404);
 

app/Http/Controllers/Community/Staff/WebsiteTeamApplicationsController.php

@@ -5,6 +5,7 @@ namespace App\Http\Controllers\Community\Staff;
 use App\Http\Controllers\Controller;
 use App\Models\Community\Staff\WebsiteOpenPosition;
 use App\Models\Community\Staff\WebsiteStaffApplications;
+use Illuminate\Http\RedirectResponse;
 use Illuminate\Http\Request;
 use Illuminate\View\View;
 
@@ -48,7 +49,7 @@ class WebsiteTeamApplicationsController extends Controller
         ]);
     }
 
-    public function store(Request $request, WebsiteOpenPosition $position)
+    public function store(Request $request, WebsiteOpenPosition $position): RedirectResponse
     {
         abort_unless($position->position_kind === 'team', 404);