Retrieve a workspace asset by UUID. Use this to resolve the final stored URLs and to check processing status after an async create (createAsset from a URL, or a signed upload) — the asset UUID is returned immediately but the file download / S3 upload / thumbnail generation completes in the background.

Key response fields:

• status — processing state: 0 NOT_STARTED, 1 IN_PROGRESS, 2 PROCESSING_FAILED, 3 THUMBNAIL_FAILED, 4 DONE, 10 NOT_PROCESSED.
• file_url / thumbnail — signed Simplified CDN URLs to the stored file (expire ~12h; re-fetch to refresh).
• import_state (URL imports only) — "stored": file_url is the stored CDN file, ready to use. "failed": see import_error (http_<status>, timeout, unreachable, not_an_image, import_failed). "pending" / "importing": still importing; file_url and thumbnail are empty until stored, so check again on a later step, and if it is still not stored after about a minute treat it as failed. Use only a stored file_url.
• There is no permanent public URL for a private asset: keep the asset id and call getAsset again whenever a fresh URL is needed.
• asset_type — image / video / audio / pdf / etc.
• payload — extracted media metadata (width, height, duration, format, ...).