Missing basePath prop breaks uploaded image previews

Medium Severity

The FileAttachments component now requires the basePath prop to construct remote image URLs for uploaded files, but neither PlaygroundStageInput nor TaskCompactStageInput pass this prop. Since resolvedBasePath defaults to "" and the condition checks resolvedBasePath.length > 0, uploaded image previews will never display their server-side URLs—only local previews will work, causing a degraded experience after page refresh or when local previews are cleaned up.

Originally posted by @cursor[bot] in #2654 (comment)