fix: attachment file handling - real files, inline preview, click to open

- FileService: use Storage::temporaryUrl() standard API instead of manual signed route
- FileService: added isImage() and getPreviewUrl() helpers
- Seeder: create actual files on disk instead of fake paths
- Edit Feedback: new 'Attachments' section showing all feedback files with thumbnails
- Interactions modal: image preview thumbnails + inline click-to-open
- New footer layout: edit-footer.blade.php wrapper for attachments + similar cases

app/Filament/Resources/Feedback/Pages/EditFeedback.php

@@ -142,7 +142,7 @@ class EditFeedback extends EditRecord
 
     public function getFooter(): ?View
     {
-        return view('filament.resources.feedback.similar-cases');
+        return view('filament.resources.feedback.edit-footer');
     }
 
     protected function mutateFormDataBeforeSave(array $data): array