Get a PNG URL for an illustration - use when SVG is not available to you. NOTE: SVG is preferred where you can get it (use get_illustration_svg).

Sizes: "low" (a small preview), "standard" (a mid-size raster), "hd" (the largest). "low" and "standard" work for everyone; "hd" needs an account whose plan covers this illustration, the same as SVG. The exact pixel dimensions depend on the illustration - read width/height from the response rather than assuming a fixed size.

The URL is presigned and expires in one hour. For a link to keep, use the permanent preview.url in a search result.

Args: illustration_id: The id from a search_illustrations result ctx: MCP context for API access size: "low", "standard" (default) or "hd"

Returns: {"url", "width", "height", "expires_in_seconds"}, or {"error"}. "hd" counts toward the paid-download limit: a refusal carries "retry_after_seconds".