fix: ensure invitation feature is properly gated to authorized users and guests

Signed-off-by: Miguel Nogueira <me@nogueira.codes>

app/Http/Controllers/InvitationController.php

@@ -20,6 +20,8 @@ class InvitationController extends Controller
 {
     public function index()
     {
+        $this->authorize('viewAny', Invitation::class);
+
         return view('dashboard.administration.invites', [
             'invites' => Invitation::all()
         ]);
@@ -28,6 +30,8 @@ class InvitationController extends Controller
     public function requestInvite(InvitationRequest $request)
     {
 
+        $this->authorize('create', Invitation::class);
+
         $guest = Auth::guest();
         $invitation = new Invitation();
 
@@ -65,6 +69,8 @@ class InvitationController extends Controller
 
     public function approveInvite(ApproveInviteRequest $request, Invitation $invitation)
     {
+        $this->authorize('update', $invitation);
+
         $approvableStates = [
             'pending'
         ];
@@ -93,6 +99,8 @@ class InvitationController extends Controller
 
     public function denyInvite(DenyInviteRequest $request, Invitation $invitation)
     {
+        $this->authorize('update', $invitation);
+
         $declinableStates = [
           'pending'
         ];