Always currently-assigned project on invoice form

Even if the project is inactive, keeping it in the project dropdown
ensures the rest of the record can be edited.

app/Http/Controllers/InvoiceController.php

@@ -198,7 +198,7 @@ public function edit(Request $request, int $id)
         $invoice = $request->user()->invoice($id);
 
         $viewVars = [
-            'projects' => $request->user()->projectsForMenu(),
+            'projects' => $request->user()->projectsForMenu(null, $invoice->project_id),
             'model' => $invoice,
             'pageTitle' => "Edit Invoice {$invoice->number}",
             'submission_method' => 'PUT',