Add tests for featured thumbnail generation; apply Pint formatting and related edits

app/Http/Requests/Academy/UpsertAcademyPromptTemplateRequest.php

@@ -45,6 +45,7 @@ class UpsertAcademyPromptTemplateRequest extends FormRequest
             'tags.*' => ['string', 'max:60'],
             'tool_notes' => ['nullable', 'array'],
             'preview_image' => ['nullable', 'string', 'max:2048'],
+            'preview_image_file' => ['nullable', 'file', 'image', 'mimes:jpg,jpeg,png,webp', 'max:5120'],
             'featured' => ['required', 'boolean'],
             'prompt_of_week' => ['required', 'boolean'],
             'active' => ['required', 'boolean'],