Use a markdown editor for FAQ content, without file attachments

MarkdownEditor gives admins a proper toolbar/preview for FAQ content
instead of a plain textarea. File attachments are disabled since
bnfexpress's FAQ content has no attachment storage backing it.

app-modules/ai-agent/src/Filament/Pages/ManageFaqs.php

@@ -5,7 +5,7 @@ namespace Modules\AiAgent\Filament\Pages;
 use BackedEnum;
 use Filament\Actions\Action;
 use Filament\Forms\Components\KeyValue;
-use Filament\Forms\Components\Textarea;
+use Filament\Forms\Components\MarkdownEditor;
 use Filament\Pages\Page;
 use Filament\Schemas\Components\Component;
 use Filament\Support\Icons\Heroicon;
@@ -144,9 +144,9 @@ class ManageFaqs extends Page implements HasTable
     protected function formSchema(): array
     {
         return [
-            Textarea::make('content')
-                ->required()
-                ->rows(4),
+            MarkdownEditor::make('content')
+                ->fileAttachments(false)
+                ->required(),
             KeyValue::make('metadata'),
         ];
     }